Driveway Sealcoat Calculator
Calculate gallons of asphalt sealer needed for any driveway from area and number of coats.
Includes coverage rate, bucket count, and material cost.
Asphalt sealer coverage depends on the type of sealer and the condition of the driveway.
A new, smooth driveway accepts sealer evenly and uses about 80-100 sq ft per gallon for the first coat.
An older, weathered, or rough-surface driveway absorbs sealer like a sponge — coverage can drop to 50-70 sq ft per gallon, sometimes less.
The math:
gallons = area_sqft / coverage_per_gallon × number_of_coats
Coverage rates by sealer type and surface condition:
- Coal tar emulsion, smooth driveway, first coat: 80 sq ft/gal
- Coal tar emulsion, smooth driveway, second coat: 100 sq ft/gal
- Coal tar emulsion, rough/weathered, first coat: 50 sq ft/gal
- Asphalt emulsion (asphalt-based), first coat: 70 sq ft/gal
- Acrylic polymer sealer, first coat: 100 sq ft/gal
- Acrylic polymer sealer, second coat: 130 sq ft/gal
Two coats are standard for residential driveways.
The first coat fills cracks and pores; the second coat builds the wear layer.
A single coat lasts 1-2 years before fading; two coats last 3-5 years depending on traffic and climate.
A worked example.
A 600 sq ft driveway with two coats of asphalt emulsion: first coat at 70 sq ft/gal needs 8.6 gallons, second coat at 90 sq ft/gal needs 6.7 gallons.
Total: 15.3 gallons, or three 5-gallon buckets with a small amount left over.
Adding 10% waste for spillage and squeegee absorption rounds to four buckets — about $80-$120 in materials.
Coal tar versus asphalt emulsion is the big choice.
Coal tar is darker, more chemical-resistant, and lasts longer (4-6 years for two coats).
But coal tar is being phased out or banned in 30+ US states and most of Europe due to PAH groundwater contamination concerns.
Asphalt emulsion is the legal default in most jurisdictions, lasts 3-4 years for two coats, and looks slightly browner.
Acrylic polymer is the premium option — UV-resistant, long-lasting (5-7 years), and twice the cost.
A few practical points.
Coverage on the bucket is a manufacturer optimum; expect 20-30% less in real conditions, especially on a porous driveway.
Apply when the surface is bone-dry and air temp is 50-90°F with no rain forecast for 24 hours after — sealer washes off within four hours of a downpour and you have to re-coat.
Do not seal a brand-new driveway for at least 90 days; fresh asphalt has too many volatiles still off-gassing for sealer to bond properly.