Wood Finish Coverage Calculator (Polyurethane, Stain, Oil)

Polyurethane, stain and oil are sold by the quart and gallon, and a project with three coats on both sides of a tabletop uses more than most people expect. Enter the piece size or area, the finish, the number of coats and the coverage from the can, and this calculator gives the amount in quarts, gallons and millilitres and the size to buy. Picking a finish fills in a typical coverage rate; the figure on your can is always the one to use.

Finish coverage calculator

How it works

Area per coat = length × width ÷ 144 × sides (both sides plus edges adds about 15%)
Gallons = area × coats ÷ coverage per gallon × (1 + extra)
Quarts = gallons × 4; a quart covers a quarter of the gallon figure

Minwax lists 125 sq ft per quart (500 per gallon) for its fast-drying polyurethane and recommends at least two coats. Wiped finishes and penetrating stains vary far more with the wood than film finishes do.

Worked example

A 60 × 36 in tabletop finished on both sides with three coats of oil-based polyurethane at 500 sq ft per gallon, with 15% extra:

Finish: Oil-based polyurethane
Coverage per coat: 500 sq ft per gallon
Measure by: Length and width of the piece
Length: 60 in
Width: 36 in
Sides to finish: Both sides
Coats: 3
Extra for rags, brushes and the can: 15%

The calculator gives:

Finish needed: 0.83 quarts (0.21 gal, 784 ml)
Buy: 1 quart
Area per coat: 30 sq ft (2.79 m²), 3 coats
Rate used: 500 sq ft per gallon per coat (125 per quart)

Thirty square feet per coat, 90 sq ft in all, is 0.21 gallons or 0.83 quarts: one quart does it with a little over. A dining table with its apron and legs would push that to two quarts, and a gallon is usually cheaper than three quarts.

Notes and limits

The first coat on bare wood soaks in and covers less than the can says; later coats cover more. The average over three coats is close to the label.
Wipe-on polyurethane and oil/varnish blends are applied thin and partly wiped off: many thin coats, each using little. Rates for those are rough.
Penetrating stain on end grain, softwood or rough surfaces can use twice the label rate. Sand end grain finer to even it out.
Shellac and lacquer coverage depends on the cut or thinning; the defaults assume brushing consistency.
Do not pour leftovers back into the can once you have dipped a brush in them; that is part of the extra.

Frequently asked questions

How much polyurethane do I need for a table?

For a 5 × 3 ft top, about a quart covers three coats on both sides at the label rate of 125 sq ft per quart. Add the legs and apron and plan on two quarts.

How many square feet does a quart of polyurethane cover?

Minwax lists 125 sq ft per quart for its fast-drying polyurethane, per coat. Other brands are similar, 100 to 150 sq ft.

How many coats of polyurethane?

At least two; three for tabletops and floors. Sand lightly between coats.

How much stain do I need for a dresser?

A dresser has roughly 40 to 60 sq ft of visible surface. One coat of penetrating stain at about 500 sq ft per gallon needs under a pint; buy a quart to be safe and for touch-ups.

Does finish coverage include both sides?

Only if you count both sides in the area. This calculator has a both-sides option; finish both sides of solid-wood tops to keep them from warping.

Sources

Minwax Fast-Drying Polyurethane product page: coverage 125 sq ft per quart, minimum two coats

Last reviewed: 26 September 2026. The calculation is covered by automated tests with known answers taken from the sources above. Found an error? Please let us know.