MATERIAL AND PROJECT ESTIMATES
Paint Calculator
Estimate gallons of paint from wall area, coats, product coverage, and an allowance you choose.
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Enter your values and select Calculate. Your result stays on this device.
How it works
Gallons = net area × coats ÷ product coverage × (1 + allowance).
Assumptions
Uses the product coverage you enter. Primer, surface porosity, color change, texture, application loss, and container sizes can change the purchase quantity.
About this calculator
This paint calculator starts with net paintable square footage and the coverage printed for the product you plan to use. It does not hide a universal coverage assumption.
How to use it
- Measure net wall or ceiling area in square feet.
- Enter the planned number of finish coats.
- Use the manufacturer’s coverage per gallon.
- Round the result to available container sizes and account for primer separately.
Use case
paint calculator: a clear planning check
Use net paintable square footage, planned coats, product coverage, and a touch-up allowance to estimate gallons without assuming one universal coverage rate.
Estimate paint gallons from net surface area, coats, and manufacturer-provided coverage.
Method and update
Last reviewed: 2026-08-10. This tool performs the stated formula locally in your browser using the values you enter.
Frequently asked questions
How much area does a gallon of paint cover?
Coverage varies by product and surface; use the value on the manufacturer’s technical information.
Should windows and doors be removed from wall area?
Use net paintable area when you can measure openings reliably.
Does this include primer?
No. Calculate primer separately using its own stated coverage.
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