How Much Paint for a Fence (Both Sides)? Why New Cedar Drinks Twice the Coverage
The number that ruins fence budgets is the one on the can: 400 square feet per gallon. That figure is a lab result on smooth, sealed drywall, and a brand-new cedar fence is about as far from sealed drywall as a surface gets. Raw cedar is a sponge with a grain. The first coat doesn’t ride on top of the wood — it sinks in, and you find out at the bottom of the bucket that one gallon covered maybe 175 square feet instead of 400. On a fence you’re painting two sides of, that miss compounds, because everything you underestimated, you underestimated twice.
So before any paint math, the surface math. A fence that’s 6 feet tall and 100 linear feet long is 600 square feet on one face. Both sides doubles it to 1,200 square feet — and that’s the number almost everyone forgets, picturing the fence as a flat run they’ll paint once. You’re painting a wall on the street side and an identical wall on the yard side. Every gallon estimate below starts from 1,200, not 600.
Coverage: the gap between smooth and raw
Coverage on a fence isn’t one number, it’s a range that depends almost entirely on whether the wood is sealed or thirsty. Here’s what actually happens out at the bucket:
| Surface condition | Realistic coverage per gallon, one coat |
|---|---|
| Previously painted, smooth, in good shape | 300–350 sq ft |
| Weathered but sealed (old solid stain) | 250–300 sq ft |
| Rough-sawn or aged bare cedar | 150–200 sq ft |
| Brand-new, never-finished cedar (first coat) | 150–175 sq ft |
| Second coat over a sealed first coat | 300–350 sq ft |
The pattern in that table is the whole story. A previously finished fence behaves like a wall — paint sits on top and spreads. New or rough cedar does the opposite: the rough-sawn face adds real surface area the smooth measurement never counted, and the dry grain drinks the binder before it can form a film. That’s why the first coat on new wood is the expensive coat. The second coat, going over a now-sealed surface, jumps back up toward 350 — it behaves like a normal repaint because, by then, it is one. I unpack this surface-versus-coverage relationship in more detail in how many square feet a gallon of paint covers, and the logic is identical here; the fence just exaggerates it.
The gallon matrix for a 100-foot fence
Take that 6×100 fence and run it through every realistic combination — one side or both, one coat or two, smooth or rough. I’m dividing the square footage by the coverage rate and rounding to whole gallons, because you buy paint in cans, not in theoretical decimals.
| Scenario | Sq ft to cover | Rate used | Gallons (rounded up) |
|---|---|---|---|
| One side, 1 coat, smooth | 600 | 350 | 2 |
| One side, 1 coat, rough/new | 600 | 175 | 4 |
| Both sides, 1 coat, smooth | 1,200 | 350 | 4 |
| Both sides, 1 coat, rough/new | 1,200 | 175 | 7 |
| Both sides, 2 coats, smooth | 2,400 | 350 | 7 |
| Both sides, 2 coats, rough/new | 1,200 @ 175 + 1,200 @ 325 | mixed | 11 |
That bottom row is the one to stare at. Two coats on both sides of a new cedar fence is roughly 11 gallons — and if the cedar is especially rough-sawn and thirsty, sitting at 150 per gallon on coat one, it climbs toward 12 to 16 gallons for the worst, fuzziest stock. The first coat alone (1,200 ÷ 175) is about 7 gallons; the second coat over sealed wood (1,200 ÷ 325) is about 4. Seven plus four is eleven. Compare that to the same fence already painted and smooth: 7 gallons for both sides, two coats. The new wood didn’t add a little to the bill. It added four to five gallons — call it $150 to $250 in product depending on whether you’re buying solid stain or a premium fence-and-deck paint.
The rule of thumb, and why I still check it against area
Painters carry a shortcut for fences: about one gallon per 35 to 40 linear feet, per side, per coat. Run our 100-foot fence through it. One side, one coat: 100 ÷ 37.5 ≈ 2.7 gallons — call it 3. Both sides, one coat: about 5.3, so 6. Both sides, two coats: roughly 11 gallons.
That tracks the area method closely for two coats on a fence that’s been painted before, which is exactly the condition the rule of thumb was built around. Where it breaks is raw cedar’s first coat. The shortcut assumes ~325–350 sq ft per gallon baked into that 35–40 feet, and new wood is pulling 175. So I treat the linear-foot rule as a sanity check, not a purchase order: it tells me I’m in the right ballpark, and the area calculation — square footage divided by the honest coverage rate for my actual wood — tells me how many cans to put in the cart. When the two disagree by a lot, the wood is thirsty, and I trust the lower number. If you’d rather not run the division by hand, drop your fence length, height, and coats into the paint calculator and it carries the coverage rate through both sides for you.
Spraying changes the math (upward)
A sprayer is faster and lays a beautiful even film, but it is not more efficient with paint — it’s less. Overspray, atomization drift, and the fine mist that never lands add roughly 30 to 50 percent to your paint volume versus brushing or rolling. Our both-sides, two-coat, new-cedar fence at 11 gallons brushed becomes about 14 to 16 gallons sprayed (11 × 1.3 to 11 × 1.5). That’s a real cost, and it’s why I back-roll a sprayed fence: spray it on, immediately roll or brush it in. You still get speed, but the roller pushes paint into the grain instead of letting half of it drift into the neighbor’s hydrangeas.
The bumps and posts nobody measures
The flat-panel calculation undercounts, because a fence isn’t flat. Picket gaps, the edges of every board, post faces, and the top and bottom rails all present extra paintable surface your tape never recorded. Add 5 to 10 percent for posts and rails — more if it’s a picket fence where you’re cutting around dozens of individual board edges. On our 11-gallon job, 10 percent is another full gallon, so I’d buy 12 and keep the receipt on the last unopened can.
A quick note on the kind of math this is: these are planning figures, not a quote — your wood’s actual thirst, your applicator, and how heavy a hand you have all get a vote, which is why I quote coverage as bands. This isn’t financial or contractor advice; it’s the same arithmetic I run on my own fence before I drive to the store. For one more worked angle — how the same rough surface eats coats when you’re trying to bury a dark color — the dark-walls coat math runs parallel to the new-cedar problem: in both cases the surface, not the can, decides how many gallons you actually buy.
What I’d put in the cart
For a 6-foot, 100-foot fence, two coats, both sides:
- Already painted and smooth: 7 gallons, plus one for posts and rails — buy 8, return any unopened.
- New or rough cedar, brushed: 11 gallons, plus one for rails — buy 12.
- New or rough cedar, sprayed: 14 to 16 gallons. Buy 15 and back-roll.
Round every total up to the next can. An unopened gallon goes back to the store in five minutes. Running dry with one side of the fence still raw, on the one warm dry Saturday you had, does not.