Deck stain calculator

Estimate stain for deck boards and railings, including a second coat.

Deck Stain Calculator

Deck length (ft)

Deck width (ft)

Railing length (ft)

Coverage (sq ft per gallon)

Coats

Gallons to buy5

Exact gallons4.94

Surface area (sq ft)432

How it works

Deck area = length × width.
Railings: linear feet × about 3 ft high × 2 sides.
Divide by coverage (150–200 sq ft per gallon on rough wood, up to 300 on smooth) and multiply by coats.

Example: A 16 × 12 ft deck with 40 ft of railing is 432 sq ft; at 175 sq ft/gal and 2 coats you need about 5 gallons.

150–200 sq ft on rough or weathered wood, 250–300 sq ft on smooth new wood.

Semi-transparent stains usually need two thin coats; solid stains often cover in one.