How Much Deck Stain Do I Need? Gallons by Deck Size and Coverage
Part of the project planners: Planning and building a deck and Planning and building a fence.
A 12 × 16 ft deck (192 sq ft) needs about 1.0 gallons of stain for one coat at 200 square feet per gallon, and 2 gallons for two coats. The coverage of a stain is on the can, usually 150 to 300 sq ft per gallon, and it is lower for rough or new boards. The deck stain calculator works it out for your own deck, coats and railings.
Stain for common deck sizes
For the deck surface only, in gallons:
| Deck | Area | One coat at 200 sq ft/gal | Two coats at 200 | One coat at 150 |
|---|---|---|---|---|
| 10 × 10 ft | 100 sq ft | 0.5 gal | 1.0 gal | 0.7 gal |
| 12 × 12 ft | 144 sq ft | 0.7 gal | 1.4 gal | 1.0 gal |
| 12 × 16 ft | 192 sq ft | 1.0 gal | 1.9 gal | 1.3 gal |
| 16 × 20 ft | 320 sq ft | 1.6 gal | 3.2 gal | 2.1 gal |
| 20 × 24 ft | 480 sq ft | 2.4 gal | 4.8 gal | 3.2 gal |
How coverage changes the amount
For a 200 sq ft deck:
| Coverage | One coat | Two coats |
|---|---|---|
| 150 sq ft per gallon | 1.33 gal | 2.67 gal |
| 200 sq ft per gallon | 1.00 gal | 2.00 gal |
| 250 sq ft per gallon | 0.80 gal | 1.60 gal |
| 300 sq ft per gallon | 0.67 gal | 1.33 gal |
Do not forget the railings, steps and edges
The area to stain is more than the deck floor. Add the railings, balusters, steps, risers and any fascia that you will stain. A rough guide is to treat each rail and baluster face as a surface of the area it covers. For a 12 × 16 ft deck with 100 sq ft of railing the stain is 1.5 gallons for one coat.
How to stain a deck
- Clean the deck with a deck cleaner and rinse it. A brightener helps an old, grayed deck. Let it dry for a couple of days.
- Repair and sand any splinters, loose boards and raised nails.
- Choose a dry day between about 50 and 90°F, with no rain in the forecast, and out of direct hot sun.
- Stain a few boards at a time, along their length, working from one end to the other to avoid lap marks.
- Wipe off the excess if the label tells you to. Do not let it pool.
- Leave it to dry for the time on the can before you put furniture back.
Choosing a stain
- Clear and toner: show the grain, and need the most upkeep.
- Semi-transparent: add color and show the grain: the most popular.
- Solid-color: hide the grain and wear like paint. They suit an old deck and give the longest life, but can peel.
- Oil-based stains soak in more, and water-based stains dry faster and clean up with water.
See the deck materials calculator for the lumber and the fasteners. Estimates only: use the coverage on your can.
Frequently asked questions
How much stain do I need for a deck?
Divide the deck area by the coverage per gallon (150 to 300 square feet, about 200 for most stains) and multiply by the coats. A 12 × 16 ft deck (192 sq ft) takes 0.96 gallons for one coat.
How many square feet does a gallon of deck stain cover?
About 150 to 300 square feet, depending on the stain and the wood: roughly 150 for new, rough or very dry wood, 200 for typical, and 250 to 300 for smooth boards or a sealer.
Do I need two coats of deck stain?
Read the can. Many penetrating stains are one coat (a second only soaks in where the wood is dry), while a solid-color stain or a film-forming finish often takes two. Using more than one coat takes a lot more stain.
How much stain for the railings?
Add the surface of the rails and balusters. 100 sq ft of railing on a 12 × 16 ft deck raises the stain from 1.0 to 1.5 gallons.
When can I stain a new deck?
When the wood is dry enough to take the stain: the moisture content should be below about 12 to 15%. New pressure-treated lumber can take weeks to months to dry. A water-drop test helps: if water soaks in, the wood is ready.
More guides
Tools & materials for this project
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Estimates only. Quantities depend on your materials, site and supplier. Confirm important numbers before you order, and follow local building codes for anything structural.