Wood fence stain & paint calculator
Work out how many gallons of stain or paint a wood fence needs and what the material costs, from length, height, sides and coverage.
Calculator
150 ft × 6 ft over 2 sides is 1,800 sq ft — about 20.6 gal (buy 21) at 2 coats. Rough/new cedar drinks more — confirm coverage on the can.
Staining or painting a wood fence protects it from water, sun and rot and keeps it looking new — but buy too little and you stop mid-project, buy too much and you waste money. This calculator turns your fence dimensions into the face area to coat, divides by the stain’s coverage, multiplies by the number of coats, and rounds up to whole gallons. Enter a price per gallon and it also estimates the material cost.
Coverage is the one number to get right: it varies a lot with the product and the wood. New, rough or thirsty boards can drink far below the label figure on the first coat, so treat the default as a labeled typical and confirm it on your can.
Formula
Gallons come from the coated area:
face area = length × height × sidesgallons = face area ÷ coverage × coatsgallons to buy = ceil(gallons), cost = gallons to buy × $/gal
- sides — coat one side, or both (a privacy fence facing a street is usually done on both).
- coverage — sq ft one gallon covers per coat; lower for rough or bare wood.
- ceil — stain is sold by the whole gallon.
Worked example
A 150 ft, 6 ft fence, both sides, at 175 sq ft/gal coverage, 2 coats, stain at $30/gal:
area = 150 × 6 × 2 = 1,800 sq ftgallons = 1,800 ÷ 175 × 2 = 20.6 → buy 21 galcost = 21 × $30 = $630
So plan on about 21 gallons and roughly $630 in material. Drop to one side and it halves to about 11 gallons.
Background & practice
A few practical notes. The first coat on bare or previously unfinished wood soaks in well below the label coverage — if you are starting fresh, lean toward the lower end of the coverage range (or a bit under) so you are not caught short. Posts, rails and dog-ear tops add a little area beyond the flat face this tool estimates, which the round-up-to-whole-gallons step usually absorbs; on a fence with heavy framing, buy one extra gallon.
This tool sizes the material. To price a stain job that also pays for labor, use the fence staining cost tool, which adds a per-foot labor line. Planning a new fence rather than refinishing one? The fence area / paint-stain calculator covers the same math for the initial finish, and cedar owners can budget the fence itself with the cedar fence cost tool. Confirm coverage and dry times on the product label before you start.
Reference table
| Wood surface | Coverage (sq ft / gal, one coat) |
|---|---|
| Smooth or previously sealed wood | 200–250 |
| Dressed cedar / pine (typical) | 150–200 |
| Rough-sawn, weathered or brand-new thirsty wood | 100–150 |
Coverage is a labeled typical — the first coat on bare or rough wood always drinks more than the label suggests. Confirm the figure on your can and buy whole gallons.
Frequently asked questions
How much stain do I need for a fence?
Multiply length by height by the number of sides for the face area, divide by the stain coverage (about 150–200 sq ft/gal), and multiply by coats. A 150 ft, 6 ft fence coated both sides at two coats needs about 21 gallons. Round up to whole gallons.
One coat or two?
Two coats is standard for new or bare wood and gives the best protection and even color. A refresh on already-stained wood in good shape may only need one — set the coats field to match.
Why does coverage vary so much?
Rough-sawn, weathered or brand-new wood is porous and drinks stain, so a gallon covers less; smooth or previously sealed wood covers more. That is why coverage is an adjustable, labeled typical — confirm it on your can.
Do I coat one side or both?
Coat every exposed face. A fence you see from both sides — a privacy fence along a street, for instance — should be done on both, which doubles the area and the gallons.
Does this include labor?
No — this is the material (gallons and their cost) only. To add labor, use the fence staining cost calculator, which prices the job per linear foot as well.