Driveway Sealer Calculator
Find how much sealer you need to seal an asphalt driveway (blacktop, or tarmac in the UK). Enter the size of the driveway, its surface, the number of coats, and the coverage on the label to see the gallons or liters of sealer and how many pails to buy. It works for sealcoat, blacktop and asphalt sealer, filler sealer and resurfacer, and tarmac sealer or tarmac restorer.
Add more areas, such as a parking pad, or subtract areas you won't seal, such as a planter.
- Choose US or Metric. You can still change the unit of any single field.
- The first section is a Rectangle. Enter the Length and Width of the driveway. For a flared entrance, choose Trapezoid, and for a round turnaround, choose Circle.
- Use Add section for a parking pad or a path. Set a section to Subtract for areas you won't seal, such as a planter.
- Choose the Driveway surface. Pick Rough or worn if you aren't sure.
- Check the Coverage per coat. It starts at a typical value for the surface. Enter the per-coat coverage on your sealer's label, and pick the unit the label uses, such as ft² per 4.75 gal pail or m² per liter.
- Enter the number of Coats. It starts at 2.
- Check the Waste allowance. It starts at 10%. Optionally, enter a Custom pail size and a price per pail, gallon, or liter to estimate the cost.
Before you seal, fill cracks and holes with a crack filler or patch, and
brush an oil spot primer onto oil stains, as your sealer's label says. The
calculator doesn't count these products. For a concentrate that you mix
with water, enter the coverage of the mixed sealer. Dimension fields
accept whole numbers, decimals, fractions, and mixed numbers, such as
24, 12.5, 3/4, or
8 1/2.
How much driveway sealer you need
The calculator adds up the area to seal, adds the waste allowance, and multiplies by the number of coats before dividing by the coverage per coat:
Total area = net area × (1 + waste % ÷ 100)
Sealer = total area × coats ÷ coverage per coat
Pails = sealer ÷ pail size, rounded up
When the coverage is per pail, such as 300 ft² per 4.75 gal pail, total area × coats ÷ that coverage is the number of those pails before rounding up. With several sections, the calculator adds the sections set to Add and subtracts those set to Subtract. The area of each shape is calculated as follows:
| Shape | Area |
|---|---|
| Rectangle | length × width |
| Circle | π × diameter² ÷ 4 (or π × radius²) |
| Triangle (base and height) | base × height ÷ 2 |
| Triangle (three sides) | Heron's formula: √(s(s − a)(s − b)(s − c)), where s = (a + b + c) ÷ 2 |
| Trapezoid | (parallel side A + parallel side B) ÷ 2 × height |
| Ring | π × (outer diameter² − inner diameter²) ÷ 4 |
| Rectangular border | outer length × outer width − (outer length − 2 × border width) × (outer width − 2 × border width) |
| Known area | the area you enter |
Coverage and the driveway surface
Coverage is the area one pail, gallon, or liter of sealer covers in one coat. It depends on the product and on the surface. A rough, worn, or porous driveway soaks up more sealer than a smooth one, and Gardner-Gibson notes in its Black Jack FAQ that a driveway that hasn't been sealed recently needs more sealer to fill its pores and cracks. That's why the calculator asks for the surface and starts at Rough or worn.
- The US defaults come from the technical data sheet for Black Jack Drive-Maxx 1000: about 300 ft² per coat for a 4.75 gallon pail on rough or worn driveways, and 350 ft² on smooth ones.
- The Metric defaults come from the Canadian Black Jack Drive-Maxx 200: 28 m² per 17 L pail on rough or worn driveways, and 32.5 m² on smooth ones.
- Other sealers list different values. Dalton Enterprises gives 300 to 400 ft² per 4.75 gallon pail for Latex-ite Airport Grade on rough surfaces and 400 to 500 ft² on smooth ones, and JETCOAT gives 250 to 350 ft² for its driveway resurfacer.
Because sealers vary this much, the coverage on your label is the best value to use. Labels give it per pail, per gallon, or per liter, so pick the matching unit and enter the number as printed:
| The label says | Unit to pick |
|---|---|
| per gallon | ft²/gal |
| per 5 gallon pail | ft² per 5 gal pail |
| per 4.75 gallon pail | ft² per 4.75 gal pail |
| per liter | m²/L |
| per 20 liter drum | m² per 20 L pail |
| per 17 L pail | m² per 17 L pail |
| per 5 liter can | m² per 5 L pail |
For another container size, divide the area by the liters and enter it in m²/L. For example, 16 to 24 m² per 4 liters is 4 to 6 m²/L. If the label gives a different coverage for each coat, enter the lower one so you don't run short. If it gives the coverage for both coats together, set Coats to 1 and enter that value.
Tarmac sealer and restorer
The Metric defaults are for a Canadian sealcoat. Tarmac restorers sold in the UK cover more area per liter: Sika lists 4 to 6 m² per liter for Sika Tarmac Restorer, depending on how porous the surface is, and Smartseal lists 40 to 60 m² per 20 liter drum for its Tarmac Restorer. With the default coverage, the calculator shows more restorer than these products need, so enter the coverage on your label, in m²/L or m² per 20 L pail.
Coats and extra sealer
Most driveway sealers call for 2 thin coats. The Black Jack Drive-Maxx 1000 data sheet says two thin coats are needed for the best performance, and SealMaster, Sika, and Smartseal also call for two coats, so the calculator starts at 2. Dalton Enterprises says two thin coats of Latex-ite are better than one thick coat. Some sealers are made for one coat only, such as Henry HE200, so follow the number of coats on your label.
Buy a little more sealer than the area needs. The Black Jack FAQ advises this because if you run out partway, the sealer already applied cures and leaves a visible line where you stopped, the weather may change before you can go on, and a different batch or product may not match. It doesn't give an amount, so the waste allowance starts at 10%, the same as for paint. Raise it for a very porous surface. You can change it from 0% to 100%.
Pail sizes
The calculator shows how many of each common pail size you need, so you can compare them with the pails in your store.
| Where | Common sizes |
|---|---|
| US | 4.75 gallons, sold in a 5 gallon pail, and some 5 gallon pails |
| Canada | 17 L |
| UK | 5 L and 20 L |
Many US sealers fill a 5 gallon pail with 4.75 gallons and give the coverage per 4.75 gallon pail. For other sizes, such as a 4 L tub or a 55 gallon drum, enter the volume on the label as the Custom pail size.
Examples
A two-car driveway
A driveway 24 ft × 50 ft is 1,200 ft². With a 10% waste allowance, the total is 1,320 ft². Two coats on a rough or worn surface at 300 ft² per 4.75 gal pail take 1,320 × 2 ÷ 300 = 8.8 pails, or 41.80 gallons, so buy 9 pails of 4.75 gallons. On a smooth surface, at 350 ft² per pail, it takes 7.54 pails, so 8.
Metric dimensions
A driveway 6 m × 15 m is 90 m², or 99 m² with 10% added. Two coats on a rough or worn surface at 28 m² per 17 L pail take 99 × 2 ÷ 28 = 7.07 pails, or 120.21 liters, so buy 8 pails of 17 L, or 7 pails of 20 L.
FAQ
About 41.8 gallons, or 9 pails of 4.75 gallons, for a two-car driveway 24 × 50 ft with two coats on a rough or worn surface and 10% extra. Enter your driveway's size and your sealer's coverage in the calculator for your own amount.
About 300 ft² per coat on a rough or worn driveway and 350 ft² on a smooth one, for a 4.75 gallon pail of Black Jack Drive-Maxx 1000. Other sealers range from about 250 to 500 ft² per pail, depending on the product and the surface, so check the label. Two coats cover half that area.
Two thin coats for most sealers. Some are made for one coat only, so follow your label.
No. Asphalt driveway sealers are made for asphalt only, and makers such as Black Jack and JETCOAT say not to use them on concrete. A concrete sealer covers several times more area per gallon (SealMaster lists 200 to 300 ft² per gallon for its Concrete Sealer), so the surface defaults don't apply. To estimate one, enter its coverage in ft²/gal or m²/L, and the calculator uses the same formula.
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