Paint Calculator
Enter wall area and number of coats to get gallons needed.
40 ft perim × 8 ft × 2 coats ≈ 2 gallons.
What you get from the Paint Calculator
The Paint Calculator takes a room- or project-level measurement and returns the quantities you need to buy. It's aimed at homeowners planning a renovation and at handypersons quoting a small job.
Every input is labeled with the unit it expects, and results are shown in whole packages (boxes, gallons, or bundles) so what you read is what you can put in a shopping cart.
- Whole-package quantities you can order today
- Waste allowance for cuts, mistakes, and touch-ups
- Optional cost line so the budget stays visible
- Works for one room or a whole floor
Before you start
Measure twice. Walls are rarely square and floors are rarely flat, so take the longest dimension in each direction and note any bump-outs or closets separately.
If you're matching an existing product (a specific paint color, brand, or dye lot), buy 10% extra now. Reorders from a different batch often show a visible seam.
Making the estimate go further
Small changes save real money on paint. Reducing waste from 15% to 10% on a large room can pay for a nicer finish; picking one product that covers the whole space avoids batch mismatches; and buying full boxes (rather than partials) usually unlocks a better per-unit price.