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PaintingDriveway Sealer Calculator — How Much Sealcoat Do I Need?
Enter your asphalt driveway size and the number of coats to estimate sealer. Coverage varies a lot by product, so treat this as a starting point and check the pail.
How this calculator works
We multiply length × width by the number of coats and divide by about 100 sq ft per gallon — a rough middle figure. Sealcoat is thick and coverage swings widely (~70–125 sq ft/gal), so the pail’s label is the real number.
What changes how much you need
- Sealer is usually sold in 5-gallon pails — round up to whole pails.
- Two thin coats last longer than one thick coat.
- Clean the driveway and fill cracks first; sealer is not a crack filler.
- Don’t seal fresh asphalt — wait 6–12 months for it to cure.
Driveway sealer by driveway size (two coats)
At about 100 sq ft per gallon per coat. Sealer is usually sold in 5-gallon pails, so round up to whole pails.
| Driveway | Area | Gallons (2 coats) | 5-gal pails |
|---|---|---|---|
| 1-car · 10 × 20 ft | 200 sq ft | 4 gal | 1 pail |
| Single, long · 10 × 50 ft | 500 sq ft | 10 gal | 2 pails |
| 2-car · 20 × 20 ft | 400 sq ft | 8 gal | 2 pails |
| 2-car, long · 20 × 40 ft | 800 sq ft | 16 gal | 4 pails |
| 3-car · 30 × 40 ft | 1,200 sq ft | 24 gal | 5 pails |
How product coverage changes the count (800 sq ft, two coats)
Older, more porous asphalt lands at the low-coverage end; the pail’s label gives the real rate.
| Rated coverage | Gallons | 5-gal pails |
|---|---|---|
| 70 sq ft/gal | 23 gal | 5 pails |
| 100 sq ft/gal | 16 gal | 4 pails |
| 125 sq ft/gal | 13 gal | 3 pails |
Frequently asked questions
How much sealer for a 2-car driveway?
A 40×20 ft driveway (800 sq ft) at two coats needs roughly 16 gallons at ~100 sq ft/gal. That is just over three 5-gallon pails, so buy four. Check your product’s rated coverage.
How many coats of driveway sealer?
Two thin coats is standard and outlasts a single heavy coat.
When can I seal a new driveway?
Wait 6–12 months after the asphalt is laid so it fully cures, or the sealer won’t bond.
How many square feet does a 5-gallon pail of driveway sealer cover?
Roughly 350–625 sq ft per coat, because sealcoat covers about 70–125 sq ft per gallon depending on the product and how porous the asphalt is. At a typical 100 sq ft per gallon, one pail does about 500 sq ft once, or 250 sq ft at two coats.
How much does it cost to seal a driveway yourself?
Consumer sealer runs roughly $30–$70 per 5-gallon pail, so an 800 sq ft driveway at two coats (4 pails) is about $120–$280 in sealer, plus a squeegee or brush and crack filler. Premium and rubberized products sit at the top of that range.
How often should you seal an asphalt driveway?
Every 2–3 years for most driveways. Sealing every year builds up a thick layer that can crack and peel. Reseal when the surface has faded to gray and the aggregate is starting to show through.
What temperature do you need to seal a driveway?
Most sealers need at least 50°F and rising — for both the air and the pavement — with no rain for 24–48 hours. Start in the morning of a dry, warm day so the sealer cures before the evening dew; the pail lists the exact limits.