Sketch it.
We do the numbers.
Every calculator on this page answers the DIY question "How much do I need?" by turning your measurements into a shopping list: the number of bags, boards, pavers, shingle bundles, risers and treads you need to buy. The page opens with an area sheet that draws a floor, deck or patio from rectangles, triangles, circles and half circles, subtracts a cut-out shape such as a hot tub or a tree, and shows the area in square feet or square meters. All 21 calculators and 4 unit converters are free, with no signup.
Square footage
Select a yellow number to type a new size, or drag shapes to move them.
Shapes
Cut out shapes are subtracted from the total, for spaces like a hot tub or tree.
Allow around 10 percent extra for cuts. The price box is optional and takes the figure the store quotes.
The measure and convert group includes square footage, cubic yards and the unit converters; the first two are the most-used entry points. Concrete covers slabs, bag mixes, footings, columns and steps, returning every job as bag counts. Stairs gives riser and tread counts for straight, landing, L-shaped and U-shaped flights. Roofing counts shingle bundles and calculates roof pitch. Decking builds deck boards from the outline you drew on the opening sheet, then adds deck stairs, baluster spacing and deck footings. Pavers and paving handles pavers with base and sand, plus separate paver sand and paver base tools, with a UK option for slabs and blocks. A single toggle on every sheet switches between imperial and metric. A set of 34 ready-made concrete slab pages gives a direct answer for a slab of a given size.
Is this free, and do I need to create an account?
Yes, every calculator is free and there is no account or signup. You can enter measurements and get an answer immediately.
Which calculator should I use for a square footage measurement instead of a volume?
Use the square footage calculator in the measurement group when you need an area, for example flooring or painting. Use the cubic yards calculator when you need a volume, for example concrete or mulch. The answer is shown in both imperial and metric units.