The wood stain coverage calculator tells you exactly how much finish to buy for your project. Enter your surface dimensions, finish type, and number of coats to get the quantity in quarts, gallons, or liters — with a waste buffer included.
Finish Coverage Calculator
How to Calculate Wood Finish Quantity
Running out of stain mid-project means finishing half the job with a new batch that may not match. This wood stain coverage calculator prevents that by factoring in porosity, coats, and waste.
Account for All Surfaces
For a table, calculate the top, four sides, and the underside if it will be finished. For a cabinet, add the door fronts, shelves, and interior separately — interior surfaces often get fewer coats. The calculator uses a single surface; multiply results for multi-surface projects or add multiple parts together.
Porosity Matters More Than You Think
End grain absorbs 3–5× more finish than face grain. Pine and cedar absorb significantly more than maple or cherry. The first coat on open-grain woods (oak, ash) seals the pores but provides very little coverage — this is your "seal coat." Plan for an extra coat on porous woods.
Frequently Asked Questions
Is this wood stain coverage calculator free?
Yes, completely free. All calculations run in your browser.
How many square feet does a quart of wood stain cover?
A quart (32 oz / 946ml) of oil-based stain typically covers 125–175 sq ft (11.6–16.3 sq m) per coat on smooth wood. On rough or porous wood (like red oak or pine), coverage drops to 60–100 sq ft. Gel stains cover less — about 70–100 sq ft per quart. Water-based stains are similar to oil-based coverage.
How many coats of stain should I apply?
Most wiping stains require 1–2 coats. Gel stains typically 1 coat. For deeper color, apply a second coat before the first fully dries (wet-on-wet) or lightly sand and recoat. Never apply more than 3 coats of penetrating stain — the surface becomes saturated and additional coats won't penetrate.
How much varnish or polyurethane do I need?
Oil-based polyurethane covers about 500–600 sq ft per gallon per coat on smooth wood. Water-based polyurethane covers 400–500 sq ft per gallon. For a tabletop requiring 3 coats, a quart covers roughly 50 sq ft per coat — enough for a 4 ft × 4 ft table with three full coats.
Should I add extra for waste and touch-ups?
Yes — add 10–20% for waste, brush overload, and touch-ups. For large projects, round up to the next container size (quart → half-gallon → gallon). Leftover finish stores better sealed in a full container with minimal air space.