How to Calculate How Much Wood Stain You Need

Whether you're refinishing a deck, staining a fence, or finishing furniture, buying the right amount of stain prevents color mismatches from opening a new batch mid-project.

The Basic Formula

Gallons needed = Total Area (sq ft) / Coverage Rate (sq ft/gal)

Coverage Rates by Stain Type

Stain TypeCoverage (sq ft/gal)
Solid stain200–300
Semi-transparent200–300
Semi-solid150–250
Clear sealer150–200
Deck brightener200–400

Rough, weathered, or porous wood absorbs more stainβ€”use the lower end of the range.

Step-by-Step Example

Deck staining: Deck surface: 16 ft Γ— 24 ft = 384 sq ft Add railings and steps: 384 + 80 = 464 sq ft total

Using semi-transparent stain at 250 sq ft/gal: 464 / 250 = 1.86 gallons

For two coats: 1.86 Γ— 2 = 3.72 β†’ Buy 4 gallons (one extra for touch-ups)

First Coat vs. Second Coat

New or stripped wood absorbs much more stain than the second coat. Budget 15–20% more for the first coat if the wood is bare.

Fence Calculation

For a board fence, multiply linear footage Γ— fence height Γ— 2 (both sides): 80 ft fence Γ— 6 ft height Γ— 2 = 960 sq ft 960 / 250 = 3.84 gallons β†’ Buy 4 gallons for one coat

Use our wood stain calculator for decks, fences, and furniture.