Fence Stain Calculator
Calculate how many gallons of stain you need for a fence from its total surface area and the stain's coverage rate.
How this calculator works
Fence stain coverage is based on the total surface area you’re covering and how far one gallon of your chosen product spreads. This calculator divides your fence’s surface area by the stain’s coverage rate to tell you how many gallons to buy.
Formula: Gallons needed = fence surface area (both sides, if staining both) ÷ coverage rate per gallon.
Worked example
300 sq ft of fence surface, with a stain rated for 150 sq ft per gallon:
- Gallons needed: 300 ÷ 150 = 2.0 gallons
Notes
Rough-sawn or weathered wood soaks up more stain than smooth new lumber, so actual coverage can run lower than the rate printed on the can, especially on an older fence. Staining both sides of the fence roughly doubles the total area compared to staining just one face, so factor that into your surface area before calculating gallons.
How to use
Measure your fence’s total surface area in square feet, doubling it if you’re staining both sides, and enter the coverage rate per gallon from your stain product’s label. The calculator divides the two to tell you how many gallons to buy for the job.
Coverage rates vary by stain product and wood condition — check your specific product’s label and buy a little extra for a second coat or touch-ups.
Frequently asked questions
How much fence stain do I need?
Divide your fence's total surface area by the stain's coverage rate per gallon, which is usually listed on the product label. If you're staining both sides of the fence, use the combined area of both faces rather than just one side.
Does staining both sides of a fence take twice as much stain?
Roughly, yes. Staining both faces of the fence approximately doubles the surface area compared to staining just one side, so plan for close to double the gallons if you're covering front and back.
Why does my fence need more stain than the can's coverage rate suggests?
The coverage rate on a stain can is typically based on smooth, new lumber. Rough-sawn or weathered wood is more porous and soaks up more stain per square foot, so an older or textured fence can use noticeably more product than the label's stated rate implies.
How much extra stain should I buy beyond the calculated amount?
It's common practice to buy a bit more than the calculated amount to cover a second coat, touch-ups, or a more absorbent section of fence. The exact amount depends on your specific stain product and the wood's condition, so check the product label for guidance.
Estimates only. Verify quantities with your supplier before purchasing.