Fence Stain & Paint Calculator
Enter your fence size, how many sides and how many coats — get the gallons of stain or paint to buy, adjusted for how thirsty your wood is.
↺ Loaded the fence size from your last calculation. Edit any field to change it.
How much stain your fence needs
Coverage is the whole game with stain. The calculator multiplies your fence face area (length × height) by the number of sides and coats, then divides by the coverage rate printed on the can. It rounds up to whole gallons because you cannot buy a third of a can — and having a little left for touch-ups beats running dry three boards from the end.
Why a picket fence uses more than the math suggests
Length × height treats the fence as a flat wall, but a real fence has picket edges, gaps that expose the back face, rails and posts. On a solid privacy fence the flat-wall estimate is close; on a spaced picket or shadowbox fence, add 10–15% because you are effectively coating extra edges. Treat the gallons here as a floor and round generously.
Stain vs. paint
- Semi-transparent stain soaks in, shows the grain, and needs re-coating every 2–3 years. Best with two thin coats.
- Solid stain sits more on the surface, lasts longer, and often covers in one coat on previously finished wood.
- Paint covers most but can peel on fences that trap moisture; always prime bare wood first (that primer is a separate coat to budget).
Get more from every gallon
- Stain in the shade — direct sun dries stain before it can soak in, wasting product and leaving lap marks.
- Back-brush after spraying or rolling to push stain into the wood.
- Clean and dry the fence first; stain will not absorb evenly into dirty or damp wood.
Estimates only — always confirm coverage on the product you buy.
Frequently asked questions
How many gallons of stain do I need for a fence?
A gallon of fence stain covers roughly 150 to 200 square feet on smooth wood, less on rough or bare wood. A 100-foot, 6-foot-tall fence stained on both sides is about 1,200 square feet per coat — around 7 gallons for one coat at 175 sq ft/gal. This calculator does the math for your exact fence.
How much does the first coat lower coverage?
A lot. Bare, thirsty wood can drink up stain at 100 to 125 sq ft per gallon on the first coat, then 200+ on the second. If you are staining new or unsealed wood, set coverage to about 125 for the first coat.
Do I count both sides of the fence?
Only if you are finishing both sides. Set "sides" to 2 for a fence you can walk around, or 1 if only your side is being stained. Note that pickets, rails and posts add surface area, so treat the result as a solid-face minimum and round up.
One coat or two?
Two thin coats last far longer than one thick coat and give more even color. Semi-transparent stains almost always look better with two. Solid stains and paint often cover in one on previously finished wood.