Sealcoat Calculator
Calculate how many gallons of sealcoat you need for a driveway or lot, plus total cost at your price per gallon.
How this calculator works
Sealcoat is applied at a standard rate per gallon on properly prepped asphalt, so this calculator divides your total surface area by that coverage rate to get gallons needed for one coat.
Formula: Gallons = Surface area (sq ft) ÷ 80 sq ft per gallon.
Worked example
A 30 ft x 12 ft driveway (360 sq ft), $15/gallon:
- Gallons: 360 ÷ 80 = 4.50 gallons
- At $15/gallon, that’s $67.50 for one coat.
Coverage reference
| Surface area | Gallons needed (1 coat) |
|---|---|
| 200 sq ft | 2.5 gallons |
| 360 sq ft | 4.5 gallons |
| 800 sq ft | 10.0 gallons |
How to measure your driveway or lot
Measure the length and width of the paved area in feet and multiply for total square footage, adding any separate sections (like an apron or parking pad) together. Remember this result covers one coat — if you’re applying the recommended two thin coats, double the gallon figure before ordering.
Frequently asked questions
How much sealcoat coverage do I get per gallon?
About 80 square feet per gallon for a single coat on aged, absorbent asphalt. Newer or less porous asphalt can stretch coverage further, while heavily weathered or cracked asphalt soaks up more per coat.
Should I apply one thick coat or two thin coats?
Two thin coats consistently outperform one thick coat — a thick single application is more prone to lap marks, slow curing, and premature peeling, while two thin coats bond and wear more evenly. If you're doing two coats, double this calculator's result.
How much does a standard 5-gallon pail of sealer cover?
A 5-gallon pail covers roughly 400 square feet at the standard 80-square-foot-per-gallon rate, enough for a single coat on a typical single-car driveway apron. Larger driveways or lots typically need sealer purchased in bulk drums rather than pails.
Why is waste not factored in for sealcoat?
Sealcoat is a liquid applied by squeegee or spray in a controlled thickness, so there isn't cut-off material the way there is with sheet goods or units — any leftover product just goes back in the pail. If you're doing two coats, account for that by doubling the gallon result rather than adding a waste percentage.
How long should asphalt cure before sealcoating?
A newly paved driveway typically needs 90 days to fully cure before its first sealcoat application, since sealing too early can trap oils and moisture in the fresh asphalt. Repeat sealcoating on an established driveway is usually recommended every 2-3 years.
Estimates only. Verify quantities with your supplier before purchasing.