Home improvement
Home improvement and DIY calculators
Measure once, work it out properly, buy the right amount.
Most used
Paint calculatorEnter the room measurements and see how much paint to buy.Tile calculatorGive us the area and the tile size and we work out tiles and boxes.Concrete calculatorPick the shape, enter the measurements, get the volume to order.Flooring calculatorWork out the area and how many packs of flooring to buy.Brick calculatorThe brick face plus the joint decides how many fit per square metre.Gravel calculatorFor driveways, paths and base layers: volume and tons.
How it is calculated
How to use these calculators
Nearly all of them start from the same three things: an area or a length, the size of the unit or the coverage of the product, and a waste percentage. All three matter, but the one people forget is waste, and it is the reason you run out halfway through the job.
Waste: how much to add
There is no single number, but there is a sensible range:
- 5 % for large units, straight layouts and regular surfaces.
- 10 % is the default for most jobs.
- 15 % or more for diagonal layouts, rooms with many corners, or units that are awkward to cut.
What these calculators do not do
They work out material quantities for planning and buying. They do not calculate structures, loads or reinforcement. If the work affects the building's structure, you need a qualified engineer.
Home improvement calculators (18)
Paint calculatorTile calculatorFlooring calculatorWallpaper calculatorConcrete calculatorMortar calculatorBrick calculatorBlock calculatorSand calculatorGravel calculatorGrout calculatorDrywall calculatorPlaster calculatorInsulation calculatorDecking calculatorFence calculatorBaseboard calculatorCaulk calculator
Home improvement guides
How much paint do I need?The full calculation, including the deductions and waste most guides skip.How much does a gallon of paint cover?350 to 400 square feet per coat, with a lot of caveats.How to calculate how much tile you needThe grout joint changes the count more than you would expect.How much extra tile should you buy?Between 10 and 15 %, and there are concrete reasons for each.How many bricks per square foot?A standard US brick with a 3/8 in joint gives 6.55 bricks per square foot.How to calculate concreteVolume is length times width times thickness. The rest is detail that matters.