A gallon of deck stain covers about 200 square feet, but nobody wants to do the math while standing in the paint aisle. Enter your deck dimensions, coat count, and whether you're doing railings to get your gallon count.
Deck Dimensions
ft
ft
Stain Options
No Railings
Scenario: You're staining a 16 ft x 12 ft deck surface only, no railings, with 2 coats.
Result: Deck area: 192 sq ft. At 2 coats and 200 sq ft per gallon: 192 x 2 / 200 = 1.92, rounded up to 2 gallons.
Include Railings
Scenario: You're staining the same 16 ft x 12 ft deck plus all the railings, with 2 coats.
Result: Deck area: 192 sq ft. Railings add 20%, so adjusted area is 230.4 sq ft. At 2 coats: 230.4 x 2 / 200 = 2.3, rounded up to 3 gallons.
Measure the deck surface (length x width). Add 20% if you're staining railings too. Multiply by coat count, then divide by the coverage rate on the can (150-300 sq ft per gallon for most products). Semi-transparent stains average about 200 sq ft/gallon.
Most semi-transparent stains last 2-3 years. Solid stains last 3-5 years. Clear sealers need reapplication every 1-2 years. The more sun and foot traffic your deck gets, the more often it needs refinishing.
Transparent shows the most wood grain but offers the least UV protection. Semi-transparent is the most popular choice -- good grain visibility with decent protection. Solid stain hides the grain completely but lasts longest and is best for older or damaged wood.
If the old stain is peeling or flaking, yes -- strip it first. If it's simply faded and worn, a thorough cleaning with a deck cleaner and brightener is usually sufficient prep. Always apply stain to clean, dry wood.
Want to learn more before you start your project?
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