Materials calculator●
Estimate how much paint, concrete, tile or flooring a job needs, with extra for waste.
Pick the material, then enter your measurements. Nothing you enter leaves this page.
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Your measurements are used only in this browser tab. Nothing is sent, saved or tracked.
How the quantities are worked out
Paint: the wall area is the room's perimeter times the wall height, minus doors and windows, plus the ceiling if you include it. Multiply by the number of coats and divide by the coverage on the tin. Concrete: volume is length times width times thickness, plus the waste you choose, shown in cubic metres or cubic yards. Tiles: the area divided by the area of one tile, plus waste, rounded up to a whole tile, and to whole boxes if you give the tiles per box. Flooring: the area plus waste divided by the coverage of one pack, rounded up. These are estimates for planning. Rooms are rarely perfect rectangles, so measure carefully and add extra for patterns, awkward cuts and mistakes.
Percentage calculator →Common questions
How much paint do I need for a room?
Multiply the room's perimeter by the wall height, subtract doors and windows, multiply by the coats and divide by the coverage on the tin. A 4 by 3 metre room with 2.5 metre walls and two coats needs about 7 litres at 10 square metres per litre.
How much extra should I buy for waste?
Around 5% for concrete, 10% for straight tile and flooring layouts, and 15% or more for diagonal or patterned layouts.
How do I work out concrete for a slab?
Multiply length, width and thickness in the same unit to get the volume. A 5 by 4 metre slab that is 10 centimetres thick is 2 cubic metres, or 2.1 with 5% waste.
Does the tile count include grout gaps?
No. It divides the area by the tile size. For wide grout lines, add the gap to the tile size you enter.
Can I use feet and gallons?
Yes. Switch Units to Imperial. Sizes are then in feet and inches, paint in gallons and concrete in cubic yards.
Are my measurements stored?
No. Everything is calculated in your browser tab and never sent anywhere.