Driveway Sealer Calculator
Pails of asphalt sealer by driveway size and coats.
Two thin coats are the standard and usually required for warranty.
From the pail label. Weathered asphalt: 250 to 350. Smooth resealing: 400+.
You need
4 pails
Round up; running out mid-coat leaves a visible lap line.
- Driveway area
- 480 sq ft
- Total gallons
- 20 gallons
Estimates only. Verify quantities before ordering.
How this is calculated
Pails = driveway area x coats / coverage per pail, rounded up. Coverage per 5-gallon pail runs about 250 to 350 sq ft on weathered asphalt and up to 400 to 500 on smooth, previously sealed surfaces; use the figure on your pail's label.
Enter your driveway dimensions and this calculator converts them into 5-gallon pails of asphalt sealer. Coverage is the variable that matters: a smooth driveway sealed a few years ago drinks far less than gray, weathered asphalt with open pores, which is why the coverage field defaults to a conservative 300 square feet per pail and should be adjusted to match your pail's label and your surface.
Two thin coats outlast one thick one, and most manufacturers require two coats for their warranty. The second coat typically stretches further than the first because the surface is already sealed; the calculator's straight multiplication is deliberately a little conservative, which on sealer is the right side to miss on, since a partial second pail means a visible seam line where you stopped.
Sealer for common driveway sizes
Rows assume two coats at 300 sq ft per 5-gallon pail (weathered asphalt).
| Driveway | Pails | Area |
|---|---|---|
| 10 x 20 ft (parking pad) | 2 pails | 200 sq ft |
| 12 x 40 ft (single car) | 4 pails | 480 sq ft |
| 12 x 60 ft | 5 pails | 720 sq ft |
| 20 x 40 ft (double wide) | 6 pails | 800 sq ft |
| 12 x 100 ft (long drive) | 8 pails | 1,200 sq ft |
Common questions
How many square feet does a 5-gallon pail of sealer cover?
Labels typically claim 250 to 500 square feet. Reality depends on the surface: weathered, porous asphalt absorbs heavily and lands at the low end for the first coat, while a smooth driveway resealed on schedule reaches the high end. Plan on 300 per pail unless you know your surface is smooth.
How often should I seal my driveway?
Every 2 to 4 years. Sealing more often than every couple of years builds up a film that can crack and peel; waiting until the asphalt is gray and faded means the surface has already oxidized. New asphalt should cure 6 to 12 months before its first sealing.
When is the best time to seal a driveway?
A dry stretch with daytime temperatures of 60 to 85 F and no rain for 24 to 48 hours, which makes late spring through early fall the season. Avoid sealing in high heat and direct midday sun, which flash-dries the surface before it bonds.
Do cracks need filling before sealing?
Yes. Sealer is a surface coating, not a crack filler; anything wider than a hairline needs rubberized crack filler first, and potholes need patch material. Sealing over open cracks just gives water a decorated path into the base, which is what actually destroys driveways.