Deck & Fence Stain Calculator
Work out how many gallons of stain or sealer you need for a deck or fence.
How to use this stain calculator
Choose deck or fence and enter the size in feet. For a fence, pick whether you're staining one side or both. Coverage varies a lot with the wood: smooth new boards might take 250–300 sq ft per gallon, while rough, old or thirsty wood can drink so much that you only get 100–150. 200 is a sensible middle value. Check the label on your stain.
Railings, stairs and benches add surprisingly large amounts of surface. A common shortcut is to add 20–30% to the deck floor's total for them.
Coverage by wood condition
| Wood | Typical coverage per gallon |
|---|---|
| Smooth, new or planed | 250–300 sq ft |
| Weathered, a few years old | 150–250 sq ft |
| Rough-sawn or very dry | 100–150 sq ft |
The second coat usually goes further than the first because the wood is already sealed, so this calculator leans slightly toward having stain left over.
The math behind it
Deck area = length × width. Fence area = length × height × number of sides. Gallons = area × coats ÷ coverage.
Example: a 100 ft fence, 6 ft tall, stained on both sides is 1,200 sq ft. Two coats at 200 sq ft per gallon takes 12 gallons, which is two 5-gallon pails and two 1-gallon cans.
Often used together
Quick answers
How much stain do I need for a 12 × 16 deck?
The floor is 192 square feet. Two coats at about 200 sq ft per gallon is roughly 2 gallons. Add more if you're also staining railings and stairs.
How many coats of stain should a deck or fence get?
Most semi-transparent and solid stains recommend two thin coats. Some penetrating oils are meant to go on as one coat, so follow the label.
How long should new wood dry before staining?
New pressure-treated wood often needs a few weeks to a few months to dry out. Sprinkle some water on it: if it soaks in within a few minutes, it's ready.