BuildCalcFree calculators

Primer Calculator

Enter your size to get primer quantity, plus an estimated cost. Waste is included and prices are editable.

Size
Waste and price (optional)
$

Material needed

1 gallonsBuy this many
Area100 sq ft

Estimated cost

Material cost$30
Primer

How to calculate primer

Primer at about 300 square feet per gallon. Enter wall area to get gallons.

Formula: quantity = area ÷ 300 sq ft per gallons × (1 + waste %) = 1 gallons.

Worked example

Example: 10 ft × 10 ft = 100 sq ft. Quantity: 1 gallons, about $30 at $30 per gallons.

Tips

Measure the full area, then subtract large openings if you want an exact count. Order a little extra for cuts and breakage, and confirm quantities with your supplier before you buy.

Related calculators

Frequently asked questions

How much primer do I need?

Example: 10 ft × 10 ft = 100 sq ft. Quantity: 1 gallons, about $30 at $30 per gallons.

How much waste should I add?

Add 10% for straight areas and 15% for areas with many cuts, corners and openings.

Are the prices accurate?

Prices are editable estimates. The defaults are typical US figures, and your local price can be higher or lower.

Last updated 2026-10-27. Formulas checked by Bilal Mughal.