How much asphalt do I need for a 20×40 driveway?
A 20 × 40 ft driveway is 800 square feet. Paved 3 inches thick, the standard for a new residential driveway, it takes 15.2 tons of hot-mix asphalt including 5 percent extra, over a 6 in gravel base of 24.4 tons (16.3 cubic yards). A 2 in overlay on existing pavement needs 10.2 tons; a 4 in driveway for trucks or an RV needs 20.3.
Asphalt for a 20×40 driveway by thickness
| Asphalt thickness | Tons of hot mix (5% extra) | Compacted volume | Use |
|---|---|---|---|
| 2 in | 10.2 | 4.94 cu yd | overlay on existing pavement |
| 3 in | 15.2 | 7.41 cu yd | new residential driveway |
| 4 in | 20.3 | 9.88 cu yd | trucks, RV, heavy use |
Hot-mix asphalt at 145 lb per cubic foot compacted. A new driveway also needs a gravel base: 24.4 tons for 6 in, or 32.6 tons for 8 in on clay.
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What it costs to pave a 20×40 driveway
Hot mix costs $100 to $200 a ton from the plant, so the 15.2 tons for this driveway is $1,523 to $3,045 in asphalt, plus $978 to $1,467 for the gravel base. Asphalt is not a do-it-yourself material, though: it arrives at 300 °F and must be spread and rolled within minutes, so the real number is the installed price. Contractors typically quote $7 to $13 per square foot for a new driveway with base, grading, and compaction, or $5,600 to $10,400 for 800 square feet. A 2 in overlay on sound existing asphalt runs $3 to $5 per square foot, about $2,400 to $4,000. Get three quotes and ask each for the thickness in writing.
Overlay, resurface, or replace a 20×40 driveway?
- Sealcoat ($0.15 to $0.40 per square foot, $120 to $320) if the surface is gray and dry but not cracked. It is cosmetic protection, not a repair.
- Overlay 1.5 to 2 in of new asphalt over the old (10.2 tons) if the base is solid and cracks are minor. Expect 8 to 12 years.
- Replace when there are alligator cracks, potholes, or sinking spots. Those mean the base has failed and new asphalt on top will fail the same way within a few years.
- A concrete driveway of the same size would need about 10.9 cubic yards at 4 in; compare with the concrete calculator. Concrete costs more up front and lasts longer.
Common questions
How many tons of asphalt for a 20x40 driveway?
15.2 tons at 3 inches thick, 10.2 tons at 2 inches, or 20.3 tons at 4 inches, using 145 lb per cubic foot with 5 percent extra. Multiply 800 square feet by the thickness in feet, then by 145 lb, and divide by 2,000.
How much gravel under a 20x40 asphalt driveway?
24.4 tons, or 16.3 cubic yards, for a 6 in compacted base, the usual depth for cars. On clay or soft soil use 8 in, about 32.6 tons.
How much does it cost to pave a 20x40 driveway?
About $5,600 to $10,400 installed for a new 3 in asphalt driveway with base, or $2,400 to $4,000 for a 2 in overlay on existing pavement. Material alone is $1,523 to $3,045 for the asphalt and $978 to $1,467 for gravel.