Driveway sealer calculator

Divide the driveway area by the coverage per gallon and multiply by the number of coats. A 40 by 12 foot driveway is 480 square feet; sprayed at about 100 square feet per gallon, one coat takes 5 gallons, which is one 5-gallon pail.

Roughly 375 to 500 square feet per coat, depending on the product, the surface and whether you spray or squeegee it on. Spraying lays a thinner, more even coat. Your product label gives its own rate.

The surface. A smooth or recently sealed driveway takes about 100 square feet per gallon; an average one about 80; a rough, gray or never-sealed one as little as 60, because the dry asphalt soaks it up. Squeegeeing puts down a thicker coat than spraying. Contractors who dilute concentrate also quote coverage for the mixed sealer, not the concentrate, which makes their numbers look higher.

One coat is usually enough for regular maintenance. Two thin coats last longer on faded, porous or high-traffic driveways. Let the first coat dry fully before the second.

Wait until the asphalt has cured, usually 6 to 12 months after paving, so the oils in the new asphalt have time to work out.