Driveway Sealer Calculator
Find out how many gallons and pails of asphalt driveway sealer to buy, and compare doing it yourself with hiring a sealcoating crew.
Sealer to buy
You need about 8.2 gallons of sealer for 2 coats: 2 pails of 4.75 gallons.
2pails
- Gallons8.2 gal
- Area288 sq ft
- DIY costAdd a pail price
- Pro sealcoating$49–$69
Buy an extra pail for cracks and edges; most stores take back unopened pails.
Estimate only, not a quote or professional advice. Disclaimer
How it works
Pails = Gallons ÷ Pail size, rounded up
Coverage is the number that changes most between products. Ready-to-use retail sealers list coverage on the pail. Contractor concentrates are thinned with water and sand before use; SealMaster, for example, lists 50–60 sq ft per gallon of its coal tar sealer for two coats. Old, rough or porous asphalt soaks up more sealer than smooth, newer pavement.
Sealer for common driveway sizes
| Size | Gallons | Pails | Pro cost |
|---|---|---|---|
| 10 × 20 ft | 5.7 | 2 | $34–$48 |
| 12 × 24 ft | 8.2 | 2 | $49–$69 |
| 12 × 50 ft | 17.1 | 4 | $102–$144 |
| 16 × 40 ft | 18.3 | 4 | $109–$154 |
| 20 × 20 ft | 11.4 | 3 | $68–$96 |
| 24 × 24 ft | 16.5 | 4 | $98–$138 |
| 20 × 40 ft | 22.9 | 5 | $136–$192 |
| 24 × 36 ft | 24.7 | 6 | $147–$207 |
Before you seal
- Clean the surface and let it dry. Fill cracks first with a crack filler made for asphalt.
- Check the forecast: most sealers need dry weather and minimum temperatures on the label for a day or more.
- Keep cars off until the product's cure time has passed.
- Some states and cities restrict coal tar sealers. Check local rules, or choose an asphalt-emulsion or acrylic sealer.
Frequently asked questions
How much driveway sealer do I need?
Multiply the area by the number of coats and divide by the product's coverage per gallon. A 12 × 24 ft driveway (288 sq ft) with two coats at 70 sq ft per gallon per coat needs about 8.2 gallons, or 2 pails of 4.75 gallons.
How many square feet does a 5-gallon bucket of sealer cover?
It depends on the product, how porous the driveway is and how thick you apply it, so read the label. Many retail pails hold 4.75 gallons. At this calculator’s default of 70 sq ft per gallon per coat, one pail covers about 330 sq ft with one coat or about 165 sq ft with two.
Should I apply one coat or two?
Many manufacturers recommend two thin coats rather than one thick one. SealMaster, for example, specifies two coats of its coal tar sealer, with drying time in between. Thin coats dry faster and are less likely to peel.
How much does professional driveway sealing cost?
LawnStarter's October 2026 guide puts professional sealcoating at about $0.17–$0.24 per square foot, so roughly $49–$69 for a 288 sq ft driveway. Minimum charges are common on small jobs.
How often should an asphalt driveway be sealed?
Cost guides commonly suggest every 2 to 5 years. Wait until new asphalt has cured, often several months, and follow the sealer maker’s temperature and dry-weather limits.
Related calculators
Sources
- SealMaster: Coal tar pavement sealer (product page) (Checked Nov 6, 2026)
- LawnStarter: How much does an asphalt driveway cost? (Oct 19, 2026)