Stain Coverage Calculator

Calculate how much stain you need, adjusting for the surface roughness and number of coats.

Stain Needed
gallons
For all coats.

Usage Tip

Stir stain often and never shake it; pigment settles, and a quick wipe of the excess gives a more even tone.

THE MATH
gallons = area × surface multiplier × coats ÷ coverage rate
Stain soaks into wood, so rough or weathered surfaces drink more. The effective area is the real area times a surface multiplier times the coats, divided by the coverage rate.
Enter the surface area, the stain coverage rate, the number of coats, and the surface type.
Rough-sawn and weathered wood use more than smooth, planed stock.
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The calculators and tools on Formula Factory are provided for general guidance and informational purposes only. Results are estimates based on standard formulas and the values you enter — they do not constitute professional engineering, electrical, or architectural advice. Always verify calculations with a qualified professional before making decisions for any safety-critical, code-compliance, or commercial application. Formula Factory makes no representations or warranties as to the accuracy or completeness of any result, and accepts no liability for errors, omissions, or any outcomes arising from reliance on this information.