Fence Stain Calculator
A fence stain calculator divides the fence area you will coat by the stain's coverage per gallon: 300 sq ft at 150 sq ft per gallon needs 2.0 gallons per coat.
How much stain do I need for my fence?
A fence stain calculator divides the area you plan to coat by how far one gallon spreads. Find the fence area as length × height, double it if you are doing both sides, then divide by the coverage printed on the can. A fence with 300 sq ft of surface and a stain rated at 150 sq ft per gallon needs 2.0 gallons for one coat.
Type the total fence area and the coverage rate into the calculator. It returns gallons per coat. Multiply by the number of coats on the label, then round up to whole cans.
The formula in plain words
- One side = fence length × fence height
- Area to stain = one side × number of sides
- Gallons per coat = area ÷ coverage per gallon
- Total = gallons per coat × coats
The calculator handles the third line. Coverage is the number you control. Change it to match your wood and product, and the result changes with it.
Worked examples
All results match the calculator.
- Default: 300 sq ft at 150 sq ft per gallon
- Gallons: 300 ÷ 150 = 2.00 gal
- That is a 50 ft run of 6 ft fence, one side
- Backyard privacy fence, 100 ft long, 6 ft tall, both sides, rough-sawn cedar
- One side: 100 × 6 = 600 sq ft
- Both sides: 1,200 sq ft
- At 150 sq ft per gallon: 1,200 ÷ 150 = 8.00 gal per coat
- If the same fence were smooth new pine and the can’s 250 sq ft rate held: 4.80 gal
Rough wood nearly doubles the stain on this fence. That is the reason to test a section before buying for the whole job.
- Picket fence, 80 ft long, 3 ft tall, both sides, 200 sq ft per gallon
- One side: 80 × 3 = 240 sq ft
- Both sides: 480 sq ft
- Gallons: 480 ÷ 200 = 2.40 gal
Gaps between pickets save some stain, but every picket edge and the rails take extra. For planning, treat the fence as solid.
Fence area by size
Both sides, treating the fence as a solid face.
| Fence length | 4 ft tall | 6 ft tall | 8 ft tall |
|---|---|---|---|
| 50 ft | 400 sq ft | 600 sq ft | 800 sq ft |
| 100 ft | 800 sq ft | 1,200 sq ft | 1,600 sq ft |
| 150 ft | 1,200 sq ft | 1,800 sq ft | 2,400 sq ft |
| 200 ft | 1,600 sq ft | 2,400 sq ft | 3,200 sq ft |
Divide by your coverage rate. A 150 ft, 6 ft fence at 150 sq ft per gallon takes 12 gallons per coat.
What changes coverage
| Condition | Effect on coverage |
|---|---|
| Smooth, new, planed boards | Close to label rate |
| Rough-sawn boards | Noticeably lower |
| Weathered, gray, or dry wood | Lower on the first coat |
| Second coat | Usually goes further than the first |
| Sprayer without back-brushing | More lost to overspray |
| Solid-color stain | Often covers more area than penetrating oil |
How to measure
- Measure the fence length along the ground, including gates.
- Measure height from the ground to the top of the boards.
- Add posts and caps if they stick up above the boards.
- Decide on one or both sides before you multiply.
- Read coverage from your exact product’s label, not a generic number.
Prep that affects the amount
Clean the fence and let it dry for the time the label states. Stain over dirt and mildew does not soak in evenly and you end up applying more to get an even color. New pressure-treated wood often needs to dry out before it takes stain; the product label says how long.
Common mistakes
- Measuring one side and staining two. The most common reason people run out halfway.
- Using the smooth-wood rate on old fences. Do a test patch first.
- Staining in direct hot sun. Stain flashes off before it soaks in, leaving lap marks.
- Not boxing the cans. Two batches can differ in tint.
Related calculators
For deck boards, use the deck stain calculator. Planning a new fence first? Count posts with the privacy fence calculator and boards with the fence picket calculator.
Frequently asked questions
How much fence stain do I need?
Multiply fence length by height to get one face, double it if you are staining both sides, then divide by the coverage on the can. A 100 ft fence 6 ft tall is 600 sq ft per side, or 1,200 sq ft for both. At 150 sq ft per gallon that is 8 gallons per coat.
Does staining both sides of a fence take twice as much stain?
Close to it. The back face is the same size as the front. The back of a typical privacy fence also has rails and post faces exposed, so it often takes a little more, not less. Enter the combined area in the calculator.
Why does my fence need more stain than the can's coverage rate suggests?
Labels usually quote coverage on smooth, new wood. Rough-sawn boards, weathered gray wood, and dry cedar soak up more, and coverage can fall to well under half the smooth-wood figure on the first coat. Do a test on one section, see how far a gallon goes, and set the coverage box to match.
Do I need two coats of fence stain?
That depends on the product. Many semi-transparent and solid stains call for two coats, often applied wet-on-wet, while some penetrating oils are one coat. If your stain needs two, double the gallons. The second coat usually goes further than the first because the wood is already partly sealed.
How much extra stain should I buy?
Rounding up to whole gallons usually covers it. On a large fence, buy all the stain at once and mix the cans together (box them) so the color stays even from one end to the other.
Estimates only. Verify quantities with your supplier before purchasing.