Tool
Fence Stain and Paint Calculator
Finishing a fence is a square-footage problem, not a linear-foot one. Enter the length and height, say whether you are doing one side or both, choose one coat or two, and set the coverage rate from your own can, and this tool returns the square footage and the gallons to buy.
Getting this wrong is expensive in a specific way: stain is sold by the gallon, and a job that runs out mid-fence leaves a visible seam where the next pail starts. Buying the spare gallon is cheaper than the second trip.
Surfaces
Coats
Stain or paint needed
8 gal
1,800 ft² to cover at 250 ft² per gallon
- Fence face area (one side)
- 900 ft²
- Surfaces
- Both sides
- Coats
- 1
- Buy with 10% spare
- 8 gal
Coverage printed on the can is for a smooth, prepared surface. Rough-sawn cedar and weathered boards drink more, so buy the spare gallon — leftover stain keeps for touch-ups.
Coverage is the number that matters
Every can lists a coverage rate, and it is the only figure that changes the answer meaningfully. A typical fence stain on rough-sawn wood covers about 250 square feet per gallon in one coat. A solid-body stain or paint on smooth lumber can reach 300 to 400 square feet. Weathered boards that have grayed out drink more than new ones, so older fences often land at the lower end.
If your can does not state a rating, use 250 as a starting point, buy the spare gallon, and note what you actually used. The next time you finish the fence you will know exactly.
One side or two
- One side, one coat: the minimum, and the least protection a new fence can have.
- Both sides, one coat: the balanced option, and the one that keeps boards from cupping.
- Both sides, two coats: the longest-lasting finish, and the baseline if the fence is cedar or you are using a clear sealer.
- One side, two coats: only worth it when the back is inaccessible or the neighbor declines.
Applying it without wasting a gallon
Spray and back-brush is the fastest method for a long run: the sprayer covers the field of the board, and a brush or roller follows immediately to work the finish into the grain and the gaps, which a sprayer alone misses. Work in shade, avoid direct sun, and stop when the temperature drops below about 50°F, because most stains will not cure below that.
Two thin coats always beat one thick one. A heavy coat skins over on the surface, traps solvent underneath and dries unevenly, which shows up as a patchy finish within a season.
Common questions
- How much stain does a 150 foot fence need?
- A 6 foot fence 150 feet long has 900 square feet of face per side. At a typical 250 square feet per gallon, one side in one coat takes 4 gallons. Doing both sides takes 8, and both sides in two coats takes about 15 gallons, so buy by the pail rather than the can for a job that size.
- Should I stain both sides of a wood fence?
- Both sides is the right answer for the fence itself: sealing one face and leaving the other bare lets the boards take on moisture unevenly, which is what makes pickets cup and twist. Many homeowners still do one side because the neighbor rarely offers to split the cost, which is a budget decision rather than a technical one.
- How long should I wait before staining a new fence?
- Wait for the wood to dry, not for a calendar date. New pressure-treated lumber is often still wet from the mill, and stain applied over wet wood fails early. A few weeks of dry weather is typical, longer for thick posts, and a moisture meter removes the guesswork.