12 free calculators · imperial and metric
Measure twice. Buy the right amount once.
Material calculators for paint, concrete, tile, flooring, roofing, decks and more. Every page shows the formula it uses and a worked example, so you can check the number before you spend money.
Measure and plan
Inside the house
CalculatorPaint CalculatorGallons or litres for walls and ceilings, with doors and windows removed.CalculatorDrywall CalculatorSheets of drywall or plasterboard for walls and ceilings, plus screws.CalculatorWallpaper CalculatorRolls of wallpaper by room size, roll type and pattern repeat.CalculatorTile CalculatorNumber of tiles and boxes for floors and walls, with waste for your layout pattern.CalculatorFlooring CalculatorSquare footage and boxes for laminate, vinyl plank and hardwood, plus trim length.
Yard and exterior
CalculatorConcrete CalculatorCubic yards, cubic metres and bag counts for slabs, patios and pads.CalculatorGravel CalculatorCubic yards, tons and bags of gravel, crushed stone, sand or topsoil.CalculatorMulch CalculatorCubic yards, cubic metres and bag counts for garden beds at any depth.CalculatorFence CalculatorPosts, rails and pickets for a wood picket or privacy fence.CalculatorDeck CalculatorDeck boards, linear feet, joists and screws for a rectangular deck.CalculatorRoofing CalculatorRoof area, squares and shingle bundles from the house footprint and pitch.
Guides
GuideHow Many Coats of Paint Do You Need?Two coats is the usual answer, but not always the right one. The surface, the colour change and the paint itself all decide it.GuideHow Thick Should a Concrete Slab Be?Thickness decides both how strong a slab is and how much concrete you order. Here are the common starting points and what changes them.GuideHow Much Extra Tile Should You Buy?Ordering exactly the floor area almost guarantees you run short. This is how much extra to add, and why the pattern matters.GuideHow to Measure a Room for FlooringAccurate measurements decide whether you order the right number of boxes. Here is how to measure simple and awkward rooms.GuideHow Deep Should Mulch Be?The right depth suppresses weeds and holds moisture. Too much does the opposite. Here is how deep to go for each part of the garden.GuideDrywall Sheet Sizes and ThicknessesThe sheet you choose changes how many joints you tape, how many people you need and how much you buy.GuideHow to Calculate Square FootageSquare footage is the number every material estimate starts from. Here is how to get it right for simple and awkward spaces.GuideHow Much Gravel Do You Need for a Driveway?A gravel driveway is built in layers, and each one needs its own calculation. This guide walks through depth, stone type and weight.GuideRoof Pitch, Squares and Shingle BundlesRoofers talk in pitches, squares and bundles. Once you know what each means, you can check any roofing estimate yourself.GuideHow to Calculate Wallpaper RollsDividing wall area by roll area underestimates wallpaper. Counting strips gives the real number. Here is how.GuideFence Post Spacing and DepthPost spacing and depth decide how straight a fence stays over the years. Here are the common rules and when to change them.GuideDeck Board SpacingThe right gap keeps a deck draining and stops boards buckling. The right joist spacing keeps it from feeling springy.
Nothing matches that yet. Try a material such as tile, fence or mulch.
How our numbers work
Each calculator uses the same method a contractor would: measure the area or volume, add a margin for waste, and round up to the units the store sells. Coverage, yield and weight figures come from product labels and common trade practice in the United States, Canada and Australia, and you can change them where your product differs.
Switch between feet and inches or metric at the top of any calculator. The site remembers your choice.