LayoutWise

Deck & Fence Stain Calculator

Add the deck, railings, stairs and fence. You get the real area to stain — railings and stairs add more than you'd think — and the gallons to buy.

What you're staining

1. Deck
Deck length
ft
in
Deck width
ft
in
Railing length
ft
in
2. Fence
Fence length
ft
in
Fence height
ft
in
3. Stain

Stain

4.1 gal

1 x 5 gal

Area

361 sq ft

all surfaces

Coverage

175 sq ft

per gallon, per coat

Coats

2

semi-transparent

Where the stain goes

361 sq ft
  • Deck boards: 192 sq ft
  • Railings: 144 sq ft
  • Stairs: 25 sq ft

Railings count both sides of the balusters and rails; stairs count treads, risers and stringers.

Shopping list

  • ✓Semi-transparent stain: 4.1 gal — buy 1 x 5 gal
  • ✓Deck cleaner: about 2 gal ready-to-use, plus wood brightener after stripping
  • ✓Stain pad or 3/4" nap roller with an extension pole, a brush for rails and gaps, and a pump sprayer for fences

Coverage varies a lot with the wood's age and texture — do a test patch and read the can. Semi-transparent stains are usually applied wet-on-wet, so the second coat uses less.

How much stain for a deck?

The deck boards are only part of it. Railings have two sides and dozens of balusters, and stairs have treads, risers and stringers. The calculator counts railings at about 60% of their face area on both sides, which is close for typical baluster spacing.

Example: a 16' x 12' deck with 40 feet of railing and three steps is about 361 sq ft of wood. Two coats of semi-transparent stain at roughly 175 sq ft per gallon is about 4.1 gallons — one 5-gallon pail.

Coverage by stain type

StainTypical coverage per gallonCoats
Clear / transparentabout 200 sq ft1
Semi-transparentabout 175 sq ft1–2, wet-on-wet
Solid colorabout 250 sq ft2

New, rough-sawn or weathered wood soaks up a lot more — budget about 30% extra, and always check the coverage printed on the can.

Prep

Clean the wood first, strip old failing finish, and use a brightener to restore the wood's pH after stripping. Let it dry for at least a day or two before staining, and stain out of direct midday sun.

Building the deck or fence? Try the deck calculator or the fence calculator.