Driveway Sealer Calculator
Wondering how much driveway sealer do I need for your asphalt driveway? Enter the length, width, and number of coats — plus the coverage printed on your sealer's pail — and this free calculator tells you instantly how many 5-gallon pails to buy, the total gallons, and your driveway's square footage. Results update as you type.
Enter your numbers
Measure the driveway in feet. Results update as you type.
Your results
How to use this calculator
Measure your driveway's length and width in feet — for curved or irregular edges, measure the longest and widest points so you don't underestimate. Choose 1 or 2 coats (one coat is standard for a reseal; two coats for old or first-time seals), then enter the coverage per 5-gallon pail printed on your sealer's label — most products cover 250–350 sq ft per pail.
Results recalculate instantly as you type, or press Calculate to recompute on demand. The tool shows your driveway's area, the exact pails needed, how many whole pails to buy, and the total gallons. No sign-up, no downloads, and it works on any phone or computer.
How it works
The math is straightforward. First, driveway area = length × width in square feet. Then, exact pails = area × coats ÷ coverage per pail. Since sealer is only sold in whole 5-gallon pails, the tool rounds up: pails to buy = ceil(exact pails), and total gallons = pails to buy × 5.
For example, a 30 × 20 ft driveway is 600 sq ft; with one coat and 250 sq ft per pail, you need exactly 2.4 pails — so buy 3 pails (15 gallons).
This is an estimate: actual coverage varies by product and by how porous your asphalt is — always check the coverage printed on your pail's label and enter that number. Rough or weathered surfaces absorb more sealer than smooth ones.
Frequently asked questions
How much driveway sealer do I need?
Multiply your driveway's length by its width in feet to get the square footage, multiply by the number of coats, then divide by the coverage of one 5-gallon pail. For example, a 30 × 20 ft driveway is 600 sq ft; at 300 sq ft per pail, one coat needs 2 pails (round up to whole pails, since you can't buy part of a pail).
How many square feet does a 5-gallon pail of driveway sealer cover?
Most 5-gallon pails of asphalt driveway sealer cover about 250 to 350 square feet per coat. The exact coverage varies by product and by how porous your asphalt is, so always check the coverage printed on the pail label and enter that number into the calculator for the most accurate result.
Do I need one or two coats of driveway sealer?
One coat is typical for a reseal of a driveway in good condition. Two coats are recommended for a first-time seal, for old or very porous asphalt, or where the manufacturer calls for it. Two coats simply doubles the amount of sealer needed, which this calculator handles with the coats selector.
Should I buy extra sealer beyond what the calculator says?
Sealer is sold in whole 5-gallon pails, so the calculator already rounds up to the next full pail — that rounding is your built-in buffer. If your driveway is unusually rough, porous, or has many patches, buying one extra pail beyond the rounded-up amount gives you a safe margin.