Building maths guides · MeisterCalchttps://meistercalc.com/blog/feed.xml2026-11-06T00:00:00ZSai NathHow much topsoil for turf? m³ per m²https://meistercalc.com/blog/how-much-topsoil-for-turf2026-11-05T00:00:00Z2026-11-06T00:00:00ZAllow at least 100 mm of turf underlay: 0.1 m³ per m² of lawn. A 10 × 6 m lawn needs 6 m³ (9 m³ at 150 mm); dig 130 mm so turf sits flush.How much sand for a sandpit? m³ and bagshttps://meistercalc.com/blog/how-much-sand-for-a-sandpit2026-11-05T00:00:00Z2026-11-06T00:00:00ZSand in m³ = inside length × width × sand depth (m). A 1.8 × 1.8 m pit 300 mm deep holds 0.972 m³; 20 kg bags = m³ × density ÷ 20.How much mulch do I need? m³ and bagshttps://meistercalc.com/blog/how-much-mulch-do-i-need2026-11-05T00:00:00Z2026-11-06T00:00:00ZMulch in m³ = area in m² × depth in metres. A 12 m² bed at 75 mm takes 0.9 m³; 1 m³ covers 13.3 m² at 75 mm or 10 m² at 100 mm.Stair requirements in Australia (NCC 2025)https://meistercalc.com/blog/stair-rules-australia2026-11-01T00:00:00Z2026-11-06T00:00:00ZNCC 2025 stair rules for Australian houses: risers 115–190 mm, goings 240–355 mm, 2R + G 550–700 mm, 2 to 18 risers a flight, landings and handrails.Stair maths: risers, treads, stringer, openinghttps://meistercalc.com/blog/stair-calculator2026-11-01T00:00:00Z2026-11-06T00:00:00ZStair maths in mm or feet and inches: worked examples for a 2700 mm and a 9 ft rise, what the totals measure, stringer length and stair rules by country.Roof pitch converter with rafter lengthhttps://meistercalc.com/blog/roof-pitch-converter2026-11-01T00:00:00Z2026-11-06T00:00:00ZRoof pitch converter: X in 12 to degrees and per cent, worked examples for 6 in 12 and 22.5° on an 8000 mm span, common pitches and rafter line length.Noggin spacing: walls, floor joists and deckshttps://meistercalc.com/blog/noggin-spacing2026-11-01T00:00:00Z2026-11-06T00:00:00ZNoggin spacing in Australia: rows no more than 1350 mm apart in stud walls (AS 1684, 2006), 405 mm noggins at 450 centres, and when joists need blocking.mm to feet and inches converter, both wayshttps://meistercalc.com/blog/mm-to-feet-inches-converter2026-11-01T00:00:00Z2026-11-06T00:00:00Zmm to feet and inches converter, both ways, to the nearest 1/16 inch: worked examples for 3000 mm and 4800 mm, size charts, and feet-and-inch sums.How to lay out a stair stringer, step by stephttps://meistercalc.com/blog/mark-out-stair-stringer2026-11-01T00:00:00Z2026-11-06T00:00:00ZMark a stair stringer from the riser and going: set a framing square, step it along the board, drop the bottom by the tread. Worked for 2700 mm and 9 ft.Joist spacing in the UK: 400, 450 or 600 mm?https://meistercalc.com/blog/joist-spacing-uk2026-11-01T00:00:00Z2026-11-06T00:00:00ZUK joists are usually at 400 or 600 mm centres. 18 mm chipboard allows up to 450 mm, 22 mm up to 600 mm. What Approved Document A and makers say.Joist spacing NZ: deck and floor centres tablehttps://meistercalc.com/blog/joist-spacing-nz2026-11-01T00:00:00Z2026-11-06T00:00:00ZWhere NZS 3604 sets joist spacing, deck joist centres for 19 and 32 mm boards from BRANZ, plywood floor and GIB ceiling limits, and a 4.8 m bearer marked out.Joist spacing in Australia: 450 or 600 mm?https://meistercalc.com/blog/joist-spacing-australia2026-11-01T00:00:00Z2026-11-06T00:00:00ZNo single joist spacing applies in Australia: AS 1684 sizes the joist, and the flooring sets a limit, such as 450 mm for 19 mm and 600 mm for 22 mm sheets.Stair going vs tread: diagram and minimumshttps://meistercalc.com/blog/what-is-the-going-of-a-stair2026-10-28T00:00:00Z2026-11-06T00:00:00ZWhat the going of a stair measures and how it differs from the tread, with a labelled diagram, a table of stair terms, AU and UK minimums and a calculator.How to Calculate Wall Framinghttps://meistercalc.com/blog/wall-framing-calculations2026-10-28T00:00:00Z2026-11-06T00:00:00ZWork a stud wall in order: stud length, stud count, lineal metres, plates, noggings, openings and marks. Metric, with a 3.6 m wall worked through.Stud spacing in the UK: what sets ithttps://meistercalc.com/blog/stud-spacing-uk2026-10-28T00:00:00Z2026-11-06T00:00:00ZStud spacing in the UK is set by the plasterboard maker's guide or the structural design, not one rule. What decides it, and how to count studs.Stud spacing NZ: where NZS 3604 sets ithttps://meistercalc.com/blog/stud-spacing-nz2026-10-28T00:00:00Z2026-11-06T00:00:00ZWhere to read NZS 3604 for your wall, what changes the stud spacing, dwang spacing, and a set-out table with stud counts for 4.8 m and 4.9 m walls.Stud spacing Australia: 450 or 600 centres?https://meistercalc.com/blog/stud-spacing-australia2026-10-28T00:00:00Z2026-11-06T00:00:00ZWhere wall stud spacing is set in AS 1684 and NCC 2022, what moves it, the Gyprock lining limit, and a stud count table for 450 and 600 mm centres.Strip footing concrete: how to calculate ithttps://meistercalc.com/blog/strip-footing-concrete2026-10-28T00:00:00Z2026-11-06T00:00:00ZMultiply the centreline length by the width and depth, then add about 10%. A 36 m run, 600 x 300 mm, is 6.48 m³, so order about 7.13 m³.Stairwell opening size: how to work it outhttps://meistercalc.com/blog/stairwell-opening-size2026-10-28T00:00:00Z2026-11-06T00:00:00ZOpening length = (floor thickness + headroom) × going ÷ rise: 2933 mm for 200 mm of floor and 2000 mm headroom. Worked steps and the code figures.Stairs in a Tight Space: Fit a Fixed Runhttps://meistercalc.com/blog/stairs-in-a-tight-space2026-10-28T00:00:00Z2026-11-06T00:00:00ZDivide the fixed run into equal goings, then check rise, going and 2R + G. 2700 mm of rise in 2800 mm of run fails Australian limits; 13 risers fit England's.2R + G stair formula, explainedhttps://meistercalc.com/blog/stair-formula-2r-g2026-10-28T00:00:00Z2026-11-06T00:00:00Z2R + G is twice the riser plus the going. About 600 mm is a comfortable step. Worked for 240, 260 and 300 mm goings on a 2.7 m rise.Square-up diagonal calculator in mmhttps://meistercalc.com/blog/square-up-diagonal-calculator2026-10-28T00:00:00Z2026-11-06T00:00:00ZFree square-up calculator in mm: the diagonal a square frame should measure, and from two measured diagonals, how far out it is and which corners to push.Square metres to lineal metres of deckinghttps://meistercalc.com/blog/square-metres-to-lineal-metres-decking2026-10-28T00:00:00Z2026-11-06T00:00:00ZNo single factor: lineal metres per m² = 1000 ÷ (board face + gap in mm). 90 mm boards at a 5 mm gap give 10.53 m per m². Table inside.Square metres to cubic metres: the depth sumhttps://meistercalc.com/blog/square-metres-to-cubic-metres2026-10-28T00:00:00Z2026-11-06T00:00:00ZYou can't convert them: multiply the area in m² by the depth in metres. 12 m² at 100 mm deep is 1.2 m³. Depth table and the reverse sum.Maximum gap between stair spindles in the UKhttps://meistercalc.com/blog/spindle-gap-uk2026-10-28T00:00:00Z2026-11-06T00:00:00ZIn England a 100 mm sphere must not pass through stair guarding where under-fives are present. Approved Document K paragraphs and a spindle layout.Slope Percentage to Degrees: Formula and Charthttps://meistercalc.com/blog/slope-percentage-to-degrees2026-10-28T00:00:00Z2026-11-06T00:00:00ZDegrees = arctan(slope % ÷ 100). 10% is 5.71°, 1 in 12 is 8.33% or 4.76°. One chart of %, 1 in N, degrees and mm per metre.How to calculate the slope of landhttps://meistercalc.com/blog/slope-of-land2026-10-28T00:00:00Z2026-11-06T00:00:00ZSlope of land = fall ÷ horizontal distance. Get the fall from two levels, then write it as %, 1 in X or degrees. Worked example: 0.84 m over 24 m.Roof pitch to degrees chart (X/12 and 1:X)https://meistercalc.com/blog/roof-pitch-to-degrees2026-10-28T00:00:00Z2026-11-06T00:00:00ZRoof pitch in degrees is arctan(rise ÷ run). 4/12 is 18.43°, 6/12 is 26.57° and 12/12 is 45°. Full X/12, 1:X and per cent chart, with the formula.Roof Pitch Calculator App for Androidhttps://meistercalc.com/blog/roof-pitch-calculator-app2026-10-28T00:00:00Z2026-11-06T00:00:00ZMeisterCalc's Pitch calculator on Android solves rise, run, angle, % grade and X/12 from any two. Metric first, works offline. It is a paid calculator.Right angle triangle calculator in mmhttps://meistercalc.com/blog/right-angle-triangle-calculator2026-10-28T00:00:00Z2026-11-06T00:00:00ZGive a right angle triangle calculator any two of base, rise, hypotenuse or an angle and it returns the rest in mm. Nine pairs, with worked numbers.Ridge Height Calculator: Span and Pitchhttps://meistercalc.com/blog/ridge-height-calculator2026-10-28T00:00:00Z2026-11-06T00:00:00ZRidge height above the wall plate = half the span × tan(pitch). 8000 mm at 22.5° gives 1657 mm. Gable, skillion and reverse sums, in metric.1 in 14 ramp length: run = rise × 14https://meistercalc.com/blog/ramp-gradient-1-in-142026-10-28T00:00:00Z2026-11-06T00:00:00ZA 1 in 14 ramp runs 14 mm per 1 mm of rise: 150 mm needs 2.1 m. It is 7.14% or 4.09 degrees. Table, worked example and sourced rules.Rafter length from pitch and spanhttps://meistercalc.com/blog/rafter-length-from-pitch2026-10-28T00:00:00Z2026-11-06T00:00:00ZRafter line length = run ÷ cos(angle). Add the horizontal overhang to the run first. Worked in mm: 8000 span, 22.5°, 450 overhang = 4816.6 mm.Pythagoras in construction: four site jobshttps://meistercalc.com/blog/pythagoras-in-construction2026-10-28T00:00:00Z2026-11-06T00:00:00ZBuilders use Pythagoras to turn two sides of a right-angled triangle into the third: frame diagonals, stringers, rafters and braces. Worked in mm.mm to feet and inches fraction: charthttps://meistercalc.com/blog/mm-to-feet-and-inches2026-10-28T00:00:00Z2026-11-06T00:00:00ZDivide mm by 25.4, split off feet, multiply the leftover by 16 and round. 1000 mm is 3' 3 3/8". Method, carry rule, building-size chart and error.Minimum gutter fall: NCC rule and fall tablehttps://meistercalc.com/blog/minimum-fall-for-gutters2026-10-28T00:00:00Z2026-11-06T00:00:00ZThe NCC minimum fall for eaves gutters, worked out in a table for runs from 2 m to 15 m, a string-line set-out step by step, and what NZ and UK rules say.Last deck board too narrow: how to fix ithttps://meistercalc.com/blog/last-deck-board-too-narrow2026-10-28T00:00:00Z2026-11-06T00:00:00ZDo the sum before you lay: width minus whole boards and gaps. Then spread the leftover across the gaps or rip both edge boards equally. Worked in mm.Ladder distance from wall: the 1-in-4 rulehttps://meistercalc.com/blog/ladder-distance-from-wall2026-10-28T00:00:00Z2026-11-06T00:00:00ZThe 1-in-4 ladder ratio from WorkSafe NZ and SafeWork NSW, a table of foot distances for 2.4 to 6 m heights in metres and feet, the angle, and its limits.Knee brace length for a pergola, worked outhttps://meistercalc.com/blog/knee-brace-length2026-10-28T00:00:00Z2026-11-06T00:00:00ZKnee brace length is the diagonal of the drop and run: 600 mm legs at 45° give 848.5 mm. How to work it out, mark it and cut the ends, in mm.How to use a dumpy level and staffhttps://meistercalc.com/blog/how-to-use-a-dumpy-level2026-10-28T00:00:00Z2026-11-06T00:00:00ZLevel the instrument, read the staff on a benchmark to get the height of instrument, then subtract each reading for that point's level. Worked example.How to square a deck framehttps://meistercalc.com/blog/how-to-square-a-deck-frame2026-10-28T00:00:00Z2026-11-06T00:00:00ZSquare the outer frame before the joists: measure both diagonals, push the long one in by half the gap, brace it and re-measure. Worked example in mm.How to square a building, step by stephttps://meistercalc.com/blog/how-to-square-a-building2026-10-28T00:00:00Z2026-11-06T00:00:00ZFix string lines on profiles, square one corner with a 3-4-5 triangle, then check both diagonals. Worked target diagonals in mm and how far to move.How to space deck posts evenlyhttps://meistercalc.com/blog/how-to-space-deck-posts2026-10-28T00:00:00Z2026-11-06T00:00:00ZDivide the centre-to-centre length by the maximum spacing, round up to whole bays, then divide equally. Posts = bays + 1. A worked metric example.How to read a dumpy level staffhttps://meistercalc.com/blog/how-to-read-a-dumpy-level-staff2026-10-28T00:00:00Z2026-11-06T00:00:00ZRead the number below the crosshair, count the 10 mm blocks, estimate the millimetre, and write it in metres. Worked readings and the sums.How to measure an angle with a tape measurehttps://meistercalc.com/blog/how-to-measure-an-angle-with-a-tape-measure2026-10-28T00:00:00Z2026-11-06T00:00:00ZMark equal lengths on both edges, measure the gap between the marks, then read the angle from a table. 1000 mm marks and a 1414 mm gap is 90 degrees.How to mark out studs at 450 or 600 centreshttps://meistercalc.com/blog/how-to-mark-out-studs2026-10-28T00:00:00Z2026-11-06T00:00:00ZHook the tape at the plate end and mark every stud off that one reading. Marks at 450 and 600 mm centres, worked through from a 38 mm end stud.How to Divide a Length Into Equal Spaceshttps://meistercalc.com/blog/how-to-divide-a-length-into-equal-spaces2026-10-28T00:00:00Z2026-11-06T00:00:00ZDivide the length by the spacing you want, round to whole spaces, divide again for the exact gap, add one for the marks: 5500 mm is 12 spaces of 458.3 mm.How to check if a frame is squarehttps://meistercalc.com/blog/how-to-check-if-a-frame-is-square2026-10-28T00:00:00Z2026-11-06T00:00:00ZMeasure both diagonals. If opposite sides match and the diagonals are equal, the frame is square. Here's the target diagonal and how far to push if not.How to calculate trench volume and backfillhttps://meistercalc.com/blog/how-to-calculate-trench-volume2026-10-28T00:00:00Z2026-11-06T00:00:00ZTrench volume is length × width × depth in metres. A 10 m trench 0.6 m wide and 0.9 m deep is 5.4 m³, or 8.1 tonnes of gravel at 1,500 kg/m³.How to calculate roof pitch in degreeshttps://meistercalc.com/blog/how-to-calculate-roof-pitch2026-10-28T00:00:00Z2026-11-06T00:00:00ZDivide rise by run, then take the arctan: 1500 mm over 4000 mm is 20.6°. Worked metric examples, a conversion table and how to measure it on site.How to calculate reduced level: worked examplehttps://meistercalc.com/blog/how-to-calculate-reduced-level2026-10-28T00:00:00Z2026-11-06T00:00:00ZThe two-line formula for reduced level, a staff-reading example worked line by line, a negative RL, the rise and fall check, and Excel and app steps.How to calculate ramp gradienthttps://meistercalc.com/blog/how-to-calculate-ramp-gradient2026-10-28T00:00:00Z2026-11-06T00:00:00ZRamp gradient is rise ÷ run. Worked examples for the ratio (1 in N), percentage and degrees, how to measure a ramp on site, and what the rules say.1 in 100 fall in mm: how to calculate fallhttps://meistercalc.com/blog/how-to-calculate-fall2026-10-28T00:00:00Z2026-11-06T00:00:00Z1 in 100 is 10 mm per metre, 1% or 0.573 degrees: 50 mm over 5 m. Fall tables for 1 in 40 to 1 in 500 over 1 to 10 m, with sourced rules.How to calculate the diagonal of a rectanglehttps://meistercalc.com/blog/how-to-calculate-diagonal-of-a-rectangle2026-10-28T00:00:00Z2026-11-06T00:00:00ZDiagonal = √(length² + width²). A 4800 × 3600 mm frame measures 6000 mm corner to corner. Worked in mm, with how to tape it on site.How to calculate cubic metres (m³ from mm)https://meistercalc.com/blog/how-to-calculate-cubic-metres2026-10-28T00:00:00Z2026-11-06T00:00:00ZCubic metres = length × width × depth, all in metres. Divide millimetres by 1,000 first. Worked examples for slabs, rooms, holes and trenches.How much soil do I need? m³ and tonneshttps://meistercalc.com/blog/how-much-soil-do-i-need2026-10-28T00:00:00Z2026-11-06T00:00:00ZSoil in m³ = length × width × depth (m); tonnes = m³ × density ÷ 1,000. Worked raised bed, coverage per m³ and a lawn top-dress.How much screed do I need?https://meistercalc.com/blog/how-much-screed-do-i-need2026-10-28T00:00:00Z2026-11-06T00:00:00ZScreed volume is floor area × depth, plus 5 to 10%. A 20 m² floor at 65 mm is 1.30 m³, so order about 1.43 m³. Depth comes from the screed type.How much sand for paving? Tonnes per m²https://meistercalc.com/blog/how-much-sand-for-paving2026-10-28T00:00:00Z2026-11-06T00:00:00ZTonnes = length × width × bedding depth (m) × density ÷ 1,000. Worked patio example, tonnes per m² and what to ask the supplier.How much road base (or Type 1) do I need?https://meistercalc.com/blog/how-much-road-base-do-i-need2026-10-28T00:00:00Z2026-11-06T00:00:00ZTonnes = length × width × compacted depth (m) × density ÷ 1,000. Worked patio example, tonnes per m², loose vs compacted, and UK Type 1.How much gravel do I need? Tonnes per m²https://meistercalc.com/blog/how-much-gravel-do-i-need2026-10-28T00:00:00Z2026-11-06T00:00:00ZTonnes = length × width × depth (m) × density ÷ 1,000. Worked example, tonnes per square metre and a driveway with two layers.How much fall on a patio? Figures by runhttps://meistercalc.com/blog/how-much-fall-on-a-patio2026-10-28T00:00:00Z2026-11-06T00:00:00ZFall the patio away from the house. Australia's NCC grades the first metre at 25 or 50 mm; England's guidance is 1 in 60. Worked over 3, 4 and 5 m.How much extra concrete to order?https://meistercalc.com/blog/how-much-extra-concrete-to-order2026-10-28T00:00:00Z2026-11-06T00:00:00ZAdd about 10% to the exact volume, 5% for a neat job and more on rough ground. A 1.20 m³ slab becomes 1.32 m³. Why, and how minimum loads work.Cubic metre of concrete weight: about 2.4 thttps://meistercalc.com/blog/how-much-does-a-cubic-metre-of-concrete-weigh2026-10-28T00:00:00Z2026-11-06T00:00:00ZA cubic metre of concrete weighs about 2.4 tonnes (2,400 kg). Half a cubic metre is about 1.2 t. Ask your supplier for your mix.How much concrete do I need for a slab?https://meistercalc.com/blog/how-much-concrete-do-i-need2026-10-28T00:00:00Z2026-11-06T00:00:00ZMultiply length × width × depth in metres, then add 10%. A 4 × 3 m slab, 100 mm deep, is 1.20 m³: order 1.32 m³. Size table and ready-mix vs bags.How much asphalt do I need? Tonneshttps://meistercalc.com/blog/how-much-asphalt-do-i-need2026-10-28T00:00:00Z2026-11-06T00:00:00ZTonnes = length × width × compacted thickness (m) × density ÷ 1,000. Worked 10 m × 3 m driveway, tonnes per m², tarmac vs asphalt, and the base.How many studs do I need for a wall?https://meistercalc.com/blog/how-many-studs-do-i-need2026-10-28T00:00:00Z2026-11-06T00:00:00ZDivide wall length by stud spacing, round up, add one. A 3.6 m wall needs 9 studs at 450 mm centres or 7 at 600 mm. Includes a table and lineal metres.Steps for a 2.7 m or 3 m floor heighthttps://meistercalc.com/blog/how-many-steps-for-floor-height2026-10-28T00:00:00Z2026-11-06T00:00:00ZA 2.7 m floor height takes 15 risers of 180 mm. A 3 m floor height takes 17 risers of 176.5 mm. Worked sums for 2.4, 2.7, 3 m and 10 ft.Square metres per tonne of gravelhttps://meistercalc.com/blog/how-many-square-metres-does-a-tonne-of-gravel-cover2026-10-28T00:00:00Z2026-11-06T00:00:00ZOne tonne covers about 13.3 m² at 50 mm deep and 1,500 kg/m³. Table by depth and density, the formula, bulk bags and cubic metres.How many joists do I need? Deck and floorhttps://meistercalc.com/blog/how-many-joists-do-i-need2026-10-28T00:00:00Z2026-11-06T00:00:00ZDivide the length by the joist spacing, round up, add one. A 4.8 m deck needs 12 joists at 450 mm centres or 9 at 600 mm. Includes lineal metres.How many fence panels do I need?https://meistercalc.com/blog/how-many-fence-panels-do-i-need2026-10-28T00:00:00Z2026-11-06T00:00:00ZDivide the run by panel width plus one post width, round down, add one post. Worked in mm and feet, with what to do about the short bay left over.How many decking boards do I need?https://meistercalc.com/blog/how-many-decking-boards2026-10-28T00:00:00Z2026-11-06T00:00:00ZDivide deck width by board width plus gap, round up, then multiply by length. Worked example: 6 m × 4 m deck, 90 mm boards, 258 m, order 283.8 m.6x4 trailer in cubic metres: sizes and loadshttps://meistercalc.com/blog/how-many-cubic-metres-in-a-trailer2026-10-28T00:00:00Z2026-11-06T00:00:00ZInside sizes in metres for two 6x4 box trailers, their level-full volume in m³, and how much gravel their payload allows: a table, the sum and app steps.How many bulk bags of gravel do I need?https://meistercalc.com/blog/how-many-bulk-bags-of-gravel-do-i-need2026-10-28T00:00:00Z2026-11-06T00:00:00ZBags = order tonnes ÷ the bag weight on your supplier's listing, rounded up. Worked example, coverage per bag at 25 to 100 mm and common mistakes.How far out of square is acceptable?https://meistercalc.com/blog/how-far-out-of-square-is-acceptable2026-10-28T00:00:00Z2026-11-06T00:00:00ZThere is no single number. How to read the racking gap, what 12 mm means on a 4800 × 3600 mm frame, and how to judge what the next job can live with.Gravel calculator app that gives tonneshttps://meistercalc.com/blog/gravel-calculator-app2026-10-28T00:00:00Z2026-11-06T00:00:00ZMeisterCalc has Gravel, Soil and Asphalt calculators for Android. Enter length, width, depth and density to get cubic metres, tonnes and an order figure.Framing calculator app for Androidhttps://meistercalc.com/blog/framing-calculator-app2026-10-28T00:00:00Z2026-11-06T00:00:00ZYes, on Android. MeisterCalc counts studs, gives layout marks and works out raked walls, metric first. No roof framing or openings. Free tier explained.Fence post spacing: how many posts do I need?https://meistercalc.com/blog/fence-post-spacing2026-10-28T00:00:00Z2026-11-06T00:00:00ZThe bays-plus-one rule, why you round up, how to space posts evenly, a post count table for 3 m to 20 m runs, and concrete for the post holes worked out.Slope and fall ratios: %, degrees, 1 in Xhttps://meistercalc.com/blog/fall-ratio-calculator2026-10-28T00:00:00Z2026-11-06T00:00:00ZSlope and fall ratios: convert %, degrees, 1 in X and rise over run, with a conversion chart and the falls for gutters, drains and paving by code clause.Equal spacing calculator app for Androidhttps://meistercalc.com/blog/equal-spacing-calculator-app2026-10-28T00:00:00Z2026-11-06T00:00:00ZYes. MeisterCalc for Android splits a length into equal spaces and gives the gap and post count. Worked example, which tool to use, and the limits.Driveway gradient: rise ÷ run, % and 1 in Xhttps://meistercalc.com/blog/driveway-gradient2026-10-28T00:00:00Z2026-11-06T00:00:00ZDriveway gradient = rise ÷ run × 100. A 840 mm fall over 6 m is 14%, 1 in 7.14 or 7.97°. How to measure it, with sourced Australian limits.Drainage pipe fall in mm: 1 in 40, 1 in 100https://meistercalc.com/blog/drainage-pipe-fall2026-10-28T00:00:00Z2026-11-06T00:00:00ZDrainage pipe fall is the run divided by N: 1 in 40 over 8 m is 200 mm. Sourced England minimums, the far-end invert level and how to check it.Decking calculator app: boards, lineal metreshttps://meistercalc.com/blog/decking-calculator-app2026-10-28T00:00:00Z2026-11-06T00:00:00ZDecking in the MeisterCalc app: boards across and lineal metres offline, a 6 m × 4 m deck worked through, and the free calculators for the rest of the job.Decking board gap size in mmhttps://meistercalc.com/blog/decking-board-gap2026-10-28T00:00:00Z2026-11-06T00:00:00ZTimber decking gaps are 2 to 5 mm at installation, by species, width and moisture. See the table, how the gap changes your order and how to fit whole boards.Cubic metres to tonnes: gravel, soil, sandhttps://meistercalc.com/blog/cubic-metres-to-tonnes2026-10-28T00:00:00Z2026-11-06T00:00:00ZTonnes = cubic metres × density in kg/m³ ÷ 1,000. Use your supplier's density, because loose, wet and compacted loads weigh differently.How much concrete for a post holehttps://meistercalc.com/blog/concrete-for-post-holes2026-10-28T00:00:00Z2026-11-06T00:00:00ZA 300 mm wide, 800 mm deep post hole takes 0.0565 m³, about 57 litres. Here is the formula, a size table and how to turn it into bags.Concrete in m³ or yards: slabs, footings, bagshttps://meistercalc.com/blog/concrete-calculator-m32026-10-28T00:00:00Z2026-11-06T00:00:00ZConcrete in m³ or cubic yards, worked through for slabs, post holes and a strip footing, with 10% extra, bags per m³ or yd³, slab cost and rebar.Free concrete calculator app for Androidhttps://meistercalc.com/blog/concrete-calculator-app2026-10-28T00:00:00Z2026-11-06T00:00:00ZYes. MeisterCalc's Concrete calculator is free on Android: slab volume in m³ and litres, post holes in m³, plus 10% to order. It works offline.Best construction calculator app for Androidhttps://meistercalc.com/blog/best-construction-calculator-apps-android2026-10-28T00:00:00Z2026-11-06T00:00:00ZWhich construction calculator app is best on Android? 12 compared from their own listings, checked 29 Oct 2026. Our pick: MeisterCalc, which we make.Maximum Baluster Spacing NZ: 100 mm Rulehttps://meistercalc.com/blog/balustrade-gap-nz2026-10-28T00:00:00Z2026-11-06T00:00:00ZNZ barriers must stop a 100 mm sphere passing, under F4/AS1. Here is what that means for baluster gaps, with a worked layout and the clause linked.Balustrade spacing Australia: NCC rules tablehttps://meistercalc.com/blog/balustrade-gap-australia2026-10-28T00:00:00Z2026-11-06T00:00:00ZThe NCC balustrade rules in one table with clause numbers: openings, heights, the 40 mm edge gap and stairs, plus a 3000 mm run of balusters set out.Bags of concrete per m³ (20 kg)https://meistercalc.com/blog/bags-of-concrete-per-m32026-10-28T00:00:00Z2026-11-06T00:00:00ZBoral Concrete Mix 20 kg: 108 bags per m³. Cement Australia PROStrength 20 kg: about 110. Six makers' yields compared, the sum and a worked job.3-4-5 rule: set out a right angle in metrichttps://meistercalc.com/blog/3-4-5-rule2026-10-28T00:00:00Z2026-11-06T00:00:00ZMark 3 units along one line and 4 along the other from the same corner. When the gap between the marks reads 5, the corner is 90 degrees. Metric sizes.NCC 2025 adoption dates by state and territoryhttps://meistercalc.com/blog/ncc-2025-adoption-by-state2026-11-01T00:00:00Z2026-11-05T00:00:00ZNCC 2025 adoption by state, checked 1 Nov 2026: Victoria uses it now; NSW, Queensland, SA and Tasmania from 1 May 2027; WA and the ACT allow either.Can you trust ChatGPT for construction maths?https://meistercalc.com/blog/can-you-trust-chatgpt-for-construction-maths2026-11-01T00:00:00Z2026-11-05T00:00:00ZChatbots can run code for the sums, but a wrong setup, mixed units or a count rounded down still slips through. Research, a worked stair and a checklist.Brick calculator India: bricks, cement, sandhttps://meistercalc.com/blog/brick-calculator-india2026-11-01T00:00:00Z2026-11-05T00:00:00ZFree brick calculator for a 9-inch or 4½-inch wall in India: bricks less doors and windows, plus 5%, and cement bags and sand in cft for 1:6 or 1:4 mortar.Concrete mix calculator (M20): cement, sandhttps://meistercalc.com/blog/concrete-mix-calculator-india2026-11-01T00:00:00Z2026-11-01T00:00:00ZFree M20, M15 and M10 concrete mix calculator: cement in 50 kg bags, sand and aggregate in cft, m³ and brass, from the wet volume × 1.54, with IS 456 Table 9.CPC30220 Cert III Carpentry maths by unithttps://meistercalc.com/blog/cert-iii-carpentry-maths2026-11-01T00:00:00Z2026-11-01T00:00:00ZThe maths in each Cert III Carpentry unit (CPC30220, now CPC30326): quantities, setting out, framing, roofs, stairs, concrete and levels, worked in mm.Block calculator: CMU, cinder block and brickhttps://meistercalc.com/blog/block-calculator2026-11-01T00:00:00Z2026-11-01T00:00:00ZFree block calculator in metric or US units: wall area less doors and windows, plus 5%, for CMU (cinder) blocks and bricks, with bags of mortar.Construction Master Pro alternatives, Androidhttps://meistercalc.com/blog/construction-master-pro-alternatives2026-10-28T00:00:00Z2026-11-01T00:00:00ZOur pick for metric builders: MeisterCalc. 16 calculators with live diagrams, three free, a lifetime unlock. Nine Android apps compared, updated 2026-11-01.Construction calculator apps you pay for oncehttps://meistercalc.com/blog/construction-calculator-one-time-purchase2026-10-28T00:00:00Z2026-11-01T00:00:00ZMeisterCalc sells a one-time lifetime unlock and a weekly plan with a 3-day free trial. How 11 Android building calculator apps charge, updated 2026-11-01.Metric construction calculator app (mm)https://meistercalc.com/blog/construction-calculator-metric2026-10-28T00:00:00Z2026-11-01T00:00:00ZYes. MeisterCalc works in millimetres by default, with feet, inches and fractions one setting away. See what changes in each mode, with worked examples.Free construction calculator app for Androidhttps://meistercalc.com/blog/construction-calculator-app-free2026-10-28T00:00:00Z2026-11-01T00:00:00ZYes: MeisterCalc is a free construction calculator app for Android. Concrete, Stairs and Check Square stay free; the other 13 need a trial or an unlock.