How much stain does your deck need? Enter the deck size, the number of coats and what one gallon covers. You get the gallons to buy.
Your shopping list
2 galGallons to buy
1.69 galGallons needed
192 sq ftArea to coat
- Coats2
Gallon coverage is on the can. Check the weather: stain needs dry wood and mild days. Extra of 10% is included.
How to use the Deck Stain and Sealer Calculator
- Enter the deck length and width. Add railing or stair area if you will stain it.
- Pick one or two coats.
- Type the coverage from your stain can and read the gallons to buy.
The math behind it
Area = deck length x deck width + extra area
Gallons = area x coats x (1 + extra %) / coverage per gallon, rounded up
A worked example
What we typed in
- Deck length: 20 ft
- Deck width: 14 ft
- Railing and stairs area: 60 sq ft
- Number of coats: 2 coats
- One gallon covers (one coat): 200 sq ft
- Extra for mistakes and cuts: 10%
What we got
- Gallons to buy: 4 gal
- Gallons needed: 3.74 gal
- Area to coat: 340 sq ft
- Coats: 2
Tips from the job site
- Rough or old wood soaks up more stain than new wood, so coverage is lower.
- Clean and dry the deck first. Stain only on dry, mild days.
Common questions
How much stain do I need for a 12 x 16 deck?
A 192 sq ft deck with 2 coats and 250 sq ft per gallon needs about 2 gallons, with 10% extra.
How long should I wait to stain a new deck?
Follow the can. Many pressure treated boards need weeks to dry first.
See all Deck Calculators.
Last checked: (worked example and form display).