How Much Driveway Sealer Do I Need? Formula, Coverage & Worked Examples

Planning estimate — the bucket governs on coverage, and prep governs on results. Sealer is maintenance for an existing asphalt driveway, not a new surface. This guide gives you the formula, then run your drive through our driveway sealer calculator.

The formula

Gallons = length × width × coats ÷ coverage per gallon. Buckets = ceiling(gallons ÷ 5). A 600 sq ft driveway with 1 coat at 80 sq ft per gallon: 600 ÷ 80 = 7.5 gallons, or 2 five-gallon buckets. The same driveway with 2 coats at 80 sq ft per gallon needs 15 gallons, or 3 buckets. Sealer is sold in 5-gallon buckets, so the bucket count is always a round-up — a part-bucket still has to be bought.

Coverage by surface condition

Coverage is the estimate's weak point, and it depends on the surface: a smooth, previously sealed driveway takes about 100 sq ft per gallon; a rough, weathered, or never-sealed surface drinks sealer and drops toward 80 sq ft per gallon or less. If your driveway is rough, use 80 and buy the extra bucket — an unopened bucket returns to the store, but a half-sealed driveway cannot be finished from a bucket you did not buy. Always check the coverage printed on the bucket you buy; it governs over any guide.

One coat or two?

One coat is enough for a routine maintenance reseal on a driveway that was sealed within the last few years and is still in good shape. Two thin coats suit worn, faded, or first-time seals: two thin coats cure properly and cover evenly, while one thick coat can skin over, trap moisture, and peel. Let the first coat dry fully (usually 24 hours) before the second, and never seal over a damp surface.

Prep that makes a coat last

Sealer sticks to clean asphalt and peels off dirty asphalt. Sweep thoroughly, pressure-wash oil spots and algae, fill cracks wider than a pencil with crack filler, and let the surface dry fully. Do not seal within 24 hours of rain, below about 50°F, or in direct midday heat that flash-dries the coat. A coat applied over dirt or dampness fails in months instead of lasting two to three years.

Worked examples

600 sq ft, 1 coat, 80 sq ft/gal: 7.5 gallons → 2 buckets.
600 sq ft, 2 coats, 80 sq ft/gal: 15 gallons → 3 buckets.
1,200 sq ft, 2 coats, 100 sq ft/gal (smooth reseal): 24 gallons → 5 buckets.

Sealing is not paving

Sealer is a protective topcoat: it slows sun and water damage and makes the driveway look new, but it does not fix cracks, potholes, alligator cracking, drainage, or a failed base. If the driveway has those problems, fix them first — crack filler and patching for small damage, repaving for structural failure — or the sealer will fail over them within a season. Our asphalt calculator covers new asphalt quantities for a repave.

Frequently asked questions

How much driveway sealer do I need for 600 square feet?

At 1 coat and 80 sq ft per gallon, 7.5 gallons — 2 five-gallon buckets. At 100 sq ft per gallon, 6 gallons — still 2 buckets.

How many square feet does a gallon of driveway sealer cover?

Typically 80–100 sq ft per gallon per coat: about 80 on rough or first-coat surfaces, about 100 on smooth, previously sealed asphalt.

Is one coat or two coats of driveway sealer better?

Two thin coats outlast one thick coat on worn or first-time seals. One coat is enough for a routine maintenance reseal.

Can I seal a driveway with cracks in it?

Fill cracks first with crack filler. Sealer over open cracks fails quickly and does not repair them.

How long does driveway sealer last?

Typically two to three years with good prep and dry-weather application; less if applied over dirt, dampness, or unrepaired damage.

The rest of the driveway

Sealer is the finish — the asphalt calculator covers a new driveway, and the paver calculator covers a paver drive instead.