Fence stain calculator
A fence is not a deck stood on end. It has two faces, a frame on the back, and boards that are often rough-sawn and thirsty. This works out the real surface of your run, picks the right end of your stain's printed coverage range for the wood you have, and prices the job both ways — doing it yourself, or paying someone — at your own numbers.
Pre-filled with a 150-foot six-foot privacy run. Every field is editable.
Surface allowance for this style: Boards butted tight: one flat face per side. Prices move weekly and by region. Enter the unit price your yard quoted you — the defaults are round placeholders, not a market average.
What it counts
The boards, once per side you stain. The style decides how much surface the boards present per square foot of fence — a working allowance, shown below, because overlap and gaps change it. The rails and posts sit on the back of a board fence, so they are counted only when you stain both sides. A split-rail fence has no boards at all; it is all rails and posts.
| Style | Allowance per side | Why |
|---|---|---|
| Solid board (stockade, dog-ear) | × 1 | Boards butted tight: one flat face per side. |
| Board-on-board | × 1.25 | Overlapping rows: the faces plus the stepped edges each row shows. |
| Shadowbox | × 1.25 | Boards alternate across the rails, so each side shows faces, inner faces and edges. |
| Picket with gaps | × 0.75 | Boards cover part of the bay; their edges add back some of the gap. |
| Split rail | rails only | No infill: the rails all the way round, and the posts. |
Allowances are geometry, not measurements: run × height × the factor. Rails are taken as 2×4s showing three faces, posts as 4×4s showing three (four on a split-rail fence). The fence styles page draws each one.
Worked example
The default: 150 feet of six-foot solid-board fence, both sides, three rails, posts every 8 feet. That is 1,800 sq ft of board face, about 244 of rails and 105 of posts across 20 posts — roughly 2,150 sq ft in all, more than double the 900 most people picture.
On weathered boards the tool takes the low end of a 150–400 sf/gal label, so one coat is about 14.3 gallons and you buy 15: three five-gallon pails. On new smooth boards the same can reaches the high end and the job drops to six gallons. That spread is the whole reason the wood condition is an input, not a footnote.
Why the printed range is so wide
Makers print a range because the wood decides where you land. Ready Seal's data sheet says coverage "varies with wood type, application, and porosity"; Thompson's says actual coverage "will vary due to the porosity of the surface material". The Forest Products Laboratory's Wood Handbook says the same thing from the wood's side: saw-textured and weathered surfaces soak up more finish and can take two coats of semi-transparent stain, the second applied while the first is still wet.
Fence pickets are very often rough-sawn on at least one face, and an older fence is weathered on both. If you are not sure, choose the middle and buy one can over — a spare can is cheaper than a second trip and a lap mark halfway down the run.
One coat or two
Follow the can. Ready Seal's sheet says new smooth wood "will typically only take one coat the first year or two", while most porous woods "can take up to two coats". Cabot lists one recommended coat for its semi-transparent and two for its solid siding-and-fence stain. Over-applying a penetrating stain leaves a tacky surface film — the opposite of what you paid for.
New treated boards are usually still wet from treatment. Ready Seal's own threshold is 12% moisture or less before staining, read with a meter, and it warns that new wood can take "days, weeks, or longer" to get there. The deck stain guide covers the water test and the prep, which apply to a fence unchanged.
DIY or pro, honestly
The DIY line is stain only. Brushes, a pump sprayer, cleaner and brightener are extra, and so is your weekend. The pro line adds the per-square-foot rate you were quoted to the same stain, because most quotes include material. Ask whether a quote is per square foot of surface or per linear foot of fence — this tool uses surface, and the two differ by more than the height.
Pricing the fence itself rather than its finish is the fence cost calculator; the finish is a recurring line in what a fence really costs. Need the post count first? The fence post calculator gives it. For whether stain or a solid colour is the right finish at all, see deck stain vs paint.
Sources
- Ready Seal Exterior Wood Stain — Technical Data Sheet RSL-01 (Rust-Oleum) read 2026-10-18
- Thompson's WaterSeal Semi-Transparent Wood Sealer — product details read 2026-10-18
- Cabot Semi-Transparent Stain + Sealer — product details read 2026-10-18
- Cabot Siding & Fence Solid Color Stain + Sealer — product details read 2026-10-18
- USDA Forest Products Laboratory, Wood Handbook (FPL-GTR-282, 2021), ch. 16 Table 16–2 read 2026-10-18
Filed under Materials & finishes — 11 tools, guides and comparisons in this pillar.
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