Yardstickly

Deck stain calculator

Gallons or litres of deck stain, and the cheapest mix of cans or tins.

A weathered wooden deck along the side of a house
Measure in

Decimals work everywhere. On a keyboard you can also type 10' 6" or 3 1/2.

Deck
ft
ft
sq ft

Optional. Both faces of a railing count.

Stain
sq ft per gallon

Use the figure on the can, low end for rough or weathered wood.

How it works

We add the deck's floor area to any steps, railings and fascia you enter, multiply by the coats, and divide by the coverage on the can. Then we pick the mix of can or tin sizes sold in your country that wastes least. Behr lists 150–250 sq ft per gallon for its semi-transparent deck stain on new smooth wood, and 125–150 on weathered or rough wood, applied in two coats. We start at 150 sq ft per gallon (about 3.7 m² per litre); change it to match your can.

Worked examples

A 12 × 12 ft deck, two coats: 288 sq ft of staining ÷ 150 = 1.92 gallons, so 2 × 1 gallon.

A 5 × 4 m deck in Australia, two coats: 10.8 litres, so 1 × 10 L + 1 × 1 L.

Railings and steps

Railings take more stain than they look: count both faces of every baluster and rail. A quick estimate is the railing length × height × 2 for each side. Steps are tread plus riser for each step.

Common questions

How much deck stain do I need?

Deck area × coats ÷ the coverage on the can. A 12 × 12 ft deck with two coats at 150 sq ft per gallon needs about 2 gallons.

Does weathered wood need more stain?

Yes. Rough and weathered boards soak up more. Behr lists 125–150 sq ft per gallon on weathered or rough wood, against 150–250 on new smooth wood.

Guides

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