12 CALCULATORS · UPDATED FOR 2026 MATERIAL SIZES

Buy the right amount. Every time.

Enter your room's dimensions and get the exact quantity to buy — paint in gallons, flooring in boxes, drywall in sheets. Built-in waste margins so you don't end up short on install day.

Pick a calculator

12 available

Choose a material calculator, then tap Go.

Why the numbers hold up

Real waste margins

Every calculator adds the same margin a contractor would — 10% for straight cuts, up to 20% for pattern layouts — so the number you get is what to actually buy.

Rounded to real units

Results round up to whole gallons, boxes, and sheets. No fractional purchases — what you see is what you order.

The math is shown

Each result breaks down the calculation underneath it, so you can double-check it against your own tape measure.