Coming up short on a job is far more costly than a little overage. A second delivery, a return trip to the store, or a mismatched dye lot all cost more than the spare material. Every estimate should build in waste.
Typical waste factors
- Concrete: 5 to 10 percent for spillage and uneven subgrade.
- Gravel, soil, mulch and sand: about 5 percent.
- Flooring: 10 percent for a standard layout, 15 percent for diagonal or complex rooms.
- Tile: 10 percent straight, 15 percent for diagonal or patterned.
- Drywall: about 10 percent for cuts and offcuts.
Always round up
After adding waste, round up to whole bags, sheets, boxes or tiles. For tile and flooring, keep a few spares for future repairs, since matching a discontinued product later is often impossible.
Our calculators add waste for you. calculators →
Common questions
How much extra tile should I buy?
About 10 percent for a straight layout, 15 percent for diagonal or patterned, plus a few spares.
Why round up to whole bags?
Materials are sold in whole units, and a shortfall stops the job. Rounding up avoids a costly second trip.
More Calculators
Concrete New
Enter slab dimensions. Result rounds up with a 7 percent waste allowance.
Gravel New
Enter the area dimensions and depth. Result rounds up with a 5 percent waste allowance.
Mulch New
Enter the bed area and depth. Result rounds up with a 5 percent allowance.
Topsoil New
Enter the area and depth. Result rounds up with a 5 percent allowance.
Paint New
Enter total wall area and coats. Result rounds up to whole units.
Flooring New
Enter room area and the coverage printed on the box. 10 percent waste added.
Tile New
Enter the area and one tile size. 10 percent waste added.
Drywall New
Enter total area to cover. 10 percent waste added.
Paver New
Enter the patio size and one paver size. 5 percent waste added.
Sand New
Enter the area and depth. 5 percent allowance added.
Roofing New
Enter the roof surface area. 10 percent waste added. Three bundles per square.
Insulation New
Enter area to cover and the coverage printed on the package. 5 percent added.
Fence New
Enter total fence length and post spacing.
Sod New
Enter the area to cover. 5 percent allowance added.
Grass Seed New
Enter area and seeding rate. Default rates suit a new lawn.
Fertilizer New
Enter area, target nitrogen rate and the first number on the bag.
Cubic Yards New
Enter length, width and depth. No waste added.
Square Footage New
Enter length and width.
Board Foot New
Enter board dimensions and quantity.
Material Cost New
Enter quantity, unit price, tax and delivery. Figures are in your own currency.