How much do I need?

Measure once, buy once. Free calculators that turn your project's measurements into gallons, bags, yards, tons and sheets, with the usual allowance for waste already added.

Paint calculator

Gallons for walls and ceilings, by room size, coats and openings.

Common sizes: 10×10 room 10×12 room 11×12 room 12×12 room 12×14 room

Concrete calculator

Cubic yards and 80/60/40 lb bags for slabs, patios and pads.

Common sizes: 4×4 slab 10×10 slab 10×12 slab 12×12 slab 10×20 slab

Mulch calculator

Cubic yards or bags for garden beds at any depth.

Common sizes: 3×10 bed 4×8 bed 4×20 bed 5×10 bed 10×10 bed

Gravel & stone calculator

Yards and tons of gravel, stone, sand or topsoil.

Common sizes: 10×20 driveway 10×30 driveway 10×40 driveway 10×50 driveway 12×50 driveway

Tile calculator

Tiles and boxes for floors and walls, with waste by layout.

Common sizes: 5×7 floor 5×8 floor 6×8 floor 8×10 floor 10×10 floor

Drywall calculator

Sheets, screws and tape for walls and ceilings.

Common sizes: 10×10 room 10×12 room 11×12 room 12×12 room 12×14 room

Measuring for a project

Measure in feet. For a rectangle, measure the two sides. Convert inches by dividing by 12: 6 in is 0.5 ft.
Split odd shapes. Break an L-shaped room or curved bed into rectangles, run each one, and add the results.
Mind the depth units. Depth and thickness (mulch, gravel, concrete) are in inches, because that's how they're specified.
Round up, not down. A spare bag can usually be returned. A second trip in the middle of a pour can't be undone.

Every figure the calculators rely on, from paint coverage to the weight of a yard of gravel, is listed on the methods page.