How to use it 01 Open a panel. Concrete starts first; Paint , Tile , Wallpaper and Brickwork each have an address for direct linking.02 Enter metric dimensions — metres for lengths, centimetres for tile sides, millimetres for bricks and joints — and set the coefficients: nominal 1:2:4, water–cement 0.5, 10 m²/(L·coat), a 2 mm joint, a 0.53 × 10.05 m roll, a 240 × 115 × 53 mm brick. Out-of-band values warn rather than folding into the total. 03 Read the cards. Accent cards are what to buy after waste and rounding; the rest show exact litres, the spare and the dry material behind the bags. 04 Take the list. Copy it as text, publish it as a table card, send it on or add it to a report. Worked examples Default inputs; type the same values to reproduce each readout.
Panel
Defaults
Readout
Concrete
4 × 3 × 0.12 m slab; 1:2:4; w/c 0.5; 2% waste; 50 kg bags
1.44 m³ member; dry 2.262 m³ ; cement 465.32 kg = 10 bags
Paint
14 m perimeter × 2.8 m; 3.8 m² openings; 10 m²/(L·coat); 2 coats; 5 L cans; 5% waste
net 35.4 m² ; 7.434 L with waste; 2 cans ; 2.566 L spare
Tile
20 m²; 60 × 60 cm; 2 mm joint; 5% waste; 4 per box
module 0.3624 m² ; 58 pieces ; 15 boxes
Wallpaper
18 m perimeter × 2.6 m; 0.53 × 10.05 m roll; no repeat
2.7 m strips; 34 strips; 12 rolls
Brickwork
6 × 2.8 × 0.24 m wall; 1.8 m² opening; 240 × 115 × 53 mm brick; 10 mm joint; 3% waste; 1:5 mortar
3.6 m³ wall; 1,884 bricks ; 277.55 kg mortar cement = 6 bags
What the estimate multiplies Each panel is a measured quantity times a rate, rounded up to purchase units. Concrete applies the dry-volume factor 1.54 ; paint multiplies area by coats before dividing by coverage; tile divides by the grouted module; wallpaper rounds strips per roll down and rolls up; brickwork counts a brick-plus-joint module and takes mortar as wall volume minus brick volume.
Where the estimate stops
Coefficients, not design values. The nominal 1:2:4 mix is a take-off starting point. A structural mix follows strength, exposure, code and a trial batch, and typical water–cement ratios run 0.40–0.60 . Bulk densities are loose defaults — cement 1440 , dry sand 1450 , stone 1500 kg/m³ — and wet sand weighs more.
Rounding is purchase reality. Bags, cans, pieces, boxes, rolls and bricks round up, and tile rounds pieces then boxes; leftovers show the surplus you paid for.
Openings can be refused. Paint and brick stop with an error when openings equal or exceed the wall face; wallpaper deducts only full-height glazing or cabinet walls. One cubic metre of concrete is not one cubic metre of mix The default slab is 4 × 3 × 0.12 m of finished concrete: 1.44 m³ . Add 2% waste and the panel works with 1.4688 m³ placed. Then comes the step a wet-volume mix hides: loose cement, sand and stone must also fill voids and be compacted, so the panel orders 2.262 m³ of dry material — placed volume times the 1.54 dry-volume factor. Only then does 1:2:4 divide it: cement 465.32 kg (10 bags ), sand 937.09 kg , stone 1938.8 kg , water 232.66 L . Apply the ratio straight to 1.4688 m³ instead and the cement comes to 302.15 kg — 7 bags , three short for the same slab.
Where it helps A second room on the paint and tile panels A 16 m perimeter × 2.7 m room with 4.2 m² of openings reads 39 m² of wall; three coats make 117 m² painted, 12.285 L with waste, 3 cans , 2.715 L spare. A 25 m² floor in 30 cm tiles with 3 mm joints turns 272.3 exact pieces into 300 pieces and 30 boxes of 10.
Stair flights A 12-step flight — 280 mm treads, 165 mm risers, 1.2 m wide, 120 mm waist slab — is 0.89424 m³ of concrete. At 1:2:4 with 2% waste that is 6 bags of cement, 581.94 kg of sand, 1204 kg of stone and 144.48 L of water; landings are a separate slab take-off.
Patterned paper, ordered once An 18 × 2.6 m room takes 12 rolls in plain paper. A 0.32 m repeat grows each strip to 2.88 m — 0.18 m of matching waste — for the same 12 rolls ; larger repeats reduce the strips a roll yields, and half-drop matches typically need another half repeat.
Privacy All five panels compute in your browser; nothing you type is uploaded, and no list leaves the device unless you copy it yourself.
References
SAMR, GB/T 5101-2017: Fired common bricks , openstd.samr.gov.cn （访问日期：2026-10-01）— the 240 × 115 × 53 mm standard brick.
Wikipedia, Water–cement ratio , en.wikipedia.org （访问日期：2026-10-01）— the 0.40–0.60 working band.
Wikipedia, Types of concrete , en.wikipedia.org （访问日期：2026-10-01）— mix design driven by strength, exposure and code.
Wikipedia, Wallpaper , en.wikipedia.org （访问日期：2026-10-01）— pattern repeats and European 52 cm × 10 m rolls.
Wikipedia, Mortar (masonry) , en.wikipedia.org （访问日期：2026-10-01）— mortar proportions and why it stays the weaker bond.
Wikipedia, Brick , en.wikipedia.org （访问日期：2026-10-01）— bricks plus a nominal 10 mm joint form a unit size.
Calculators in this hub
Hand-picked tools, one click away. The mini versions compute live and carry your values into the full calculator.
Sources & review
Reviewed by CalcX Editorial Team
Updated 2026-10-01 SAMR, GB/T 5101-2017 Fired common bricks — the 240 × 115 × 53 mm fired common brick behind the brick panel default (accessed 2026-10-01) Wikipedia, Water–cement ratio — the 0.40–0.60 working band, the 0.35 hydration demand and why excess water lowers strength (accessed 2026-10-01) Wikipedia, Types of concrete — mix design driven by strength, exposure and code, with a typical 1:2:3 batch (accessed 2026-10-01) Wikipedia, Wallpaper — the pattern repeat as the smallest tileable rectangle, and European 52 cm × 10 m rolls (accessed 2026-10-01) Wikipedia, Mortar (masonry) — cement mortar as sand plus binder and water, the ASTM M–K proportion table, and mortar as the sacrificial element (accessed 2026-10-01) Wikipedia, Brick — bricks joined with mortar, and the unit size: actual brick plus a nominal 10 mm joint (accessed 2026-10-01)