Finish Coverage Rates

Published coverage rates for a first coat on bare wood range from about 350 square feet per gallon at the low end to 1200 at the high end across the nine finishes this site tracks — more than a 3x spread, wide enough that using one generic "a gallon covers about 400 square feet" rule for every finish leads to either running out mid-project or buying twice what a job actually needs.

The coverage and dry-time table

Finish	Coverage (sq ft/gal)	Touch-dry (hours)
Boiled linseed oil	400–600	12–24
Pure tung oil	400–500	24–48
Danish oil	350–500	4–8
Shellac	500–700	1–2
Oil-based polyurethane	400–600	6–8
Water-based polyurethane	450–600	2–4
Nitrocellulose lacquer	400–500	0.5–1
Paste wax	800–1200	0.25–0.5
Hardwax oil	500–650	8–12

These are typical manufacturer-published ranges for a first coat on bare wood, not exact figures — real coverage depends heavily on the wood's own porosity (open-grained species like oak and ash drink far more finish per square foot than closed-grain species like maple or cherry) and on application method, with sprayed and wiped applications generally covering less area per gallon than a controlled brushed coat.

A worked coverage example

Take a 40-square-foot tabletop getting two coats of oil-based polyurethane. At the coverage range's midpoint (500 sq ft/gal), two coats need 0.16 gallons — at the low end of the published range (400 sq ft/gal), the same two coats need 0.20 gallons. Either figure rounds up to a single quart can in practice, but the calculation matters more on a larger project: a full kitchen's worth of cabinetry at the same per-square-foot rates can be the difference between one gallon can and needing a second partway through a coat.

Why second and later coats need less

The coverage figures above describe a first coat on bare, uncoated wood, which soaks up more finish than any subsequent coat applied over an already-sealed surface. A second or third coat of the same finish typically covers meaningfully more area per gallon than the first, because the wood's open cell structure is already partially filled — don't plan a whole multi-coat schedule's material needs by simply multiplying the first-coat figure by the number of coats, or you'll consistently overbuy.

Matching coverage rate to drying time in a real schedule

Coverage and dry time interact in project planning more than they seem to at first: a fast-drying, low-coverage finish like paste wax lets you buff and move on within the hour, while a slow-curing high-coverage finish like tung oil demands real patience between coats but uses proportionally less material per coat. A project on a deadline benefits from weighing both columns together, not just picking a finish for its look and then discovering the schedule doesn't fit the available time.

Species-driven adjustments worth planning around

Because open-grained species consume noticeably more finish than the published range's midpoint, and closed-grained species consume less, buying toward the low end of the coverage range (meaning: assume you'll need more gallons, not fewer) is the safer default for oak, ash, and other ring-porous hardwoods, while a closed-grain species like maple or cherry can usually be planned toward the high end of the range without risk of running short mid-coat.

Sprayed finishes lose more to overspray than the table implies

The coverage figures above assume material that lands on the wood, but spraying loses a meaningful fraction of the finish to overspray and atomization that never reaches the surface at all — lacquer in particular, almost always sprayed rather than brushed, should be bought with a real overspray allowance on top of the published coverage figure, not treated as if every ounce in the can will end up on the piece. A brushed or wiped finish wastes comparatively little, which is part of why the practical coverage gap between a careful hand-applied finish and a sprayed one is often wider than the published numbers alone suggest.

Buying in the right container size

Most of these finishes are sold in quart and gallon containers, occasionally pint for the more expensive oils; a project calculated at well under half a gallon is usually better bought as a quart both for cost and because opened cans of film finishes and reactive oils have a limited shelf life once air-exposed — buying more than a project needs "to be safe" often just means throwing away a partially used, skinned-over can months later rather than actually having a useful reserve on hand.