How much do I need?

Calculators for the materials of a DIY job. Enter the size, read the amount, then check the label and your supplier before you buy.

Start with concrete How it is worked out

Concrete calculatorCubic yards and bags for a rectangular slab
Gravel calculatorCubic yards and tons for a gravel bed or base
Mulch calculatorCubic yards and bags of mulch for a bed
Paint calculatorGallons of paint for the walls of a room
Flooring calculatorSquare feet and boxes of flooring for a room

Concrete for common slab sizes

Pages with the answer worked out for each size: 10x10, 10x12, 12x12, 12x16, 12x20, 16x16, 20x20, 24x24. The full table compares them.

How it works

Volumes and areas are multiplied out, an extra percentage is added, and counts round up. Numbers that depend on the product, such as a bag's yield or a can's coverage, are fields you fill in from the label. Read the method and its limits.