Asphalt Calculator

How much asphalt do I need?

This asphalt calculator finds tons of hot-mix asphalt with one line of math: length × width × depth in feet gives cubic feet, × 145 lb per cubic foot gives pounds, and ÷ 2,000 gives tons. Plants sell asphalt by the ton, so the result is ready to read to a supplier. The cost line is tons × your price per ton, and the waste box adds 10% to the order.

Enter the paved length and width in feet and the compacted thickness in inches. The calculator does the inch-to-foot conversion for you.

The asphalt formula, step by step

1. Depth in feet = inches ÷ 12. Three inches is 0.25 ft.
2. Cubic feet = length × width × depth in feet.
3. Pounds = cubic feet × 145.
4. Tons = pounds ÷ 2,000.
5. With waste = tons × 1.10.
6. Cost = tons × price per ton.

The 145 figure is the weight of asphalt after it is rolled and compacted. Loose mix in the truck bed takes up more room, but it is the same tonnage, so using the compacted density gives the right order.

Worked examples

1. Single-car driveway: 30 ft × 12 ft at 3 in, $120 per ton

• Cubic feet: 30 × 12 × 0.25 = 90 ft³
• Pounds: 90 × 145 = 13,050 lb
• Tons: 13,050 ÷ 2,000 = 6.53 tons, or $783.00
• With the 10% box ticked: 7.18 tons, $861.30

2. Two-car driveway: 80 ft × 20 ft at 4 in, $120 per ton

• Cubic feet: 80 × 20 × 0.333 = 533.3 ft³
• Pounds: 533.3 × 145 = 77,333 lb
• Tons: 38.67 tons
• With 10% extra: 42.53 tons, $5,104.00 for material only

Example 2 is several truckloads. Ask the plant how many tons its trucks carry before you schedule paving, because the crew needs a steady supply while the mix is hot.

Asphalt coverage per ton

Compacted thickness	Area per ton	Tons per 100 sq ft
1.5 in	~110 sq ft	0.91
2 in	~83 sq ft	1.21
3 in	~55 sq ft	1.81
4 in	~41 sq ft	2.42
6 in	~28 sq ft	3.63

Typical asphalt thickness by project

Project	Asphalt (compacted)	Aggregate base
Walking path	2 in	4 in
Residential driveway	2–3 in	4–8 in
Driveway with heavy vehicles	3–4 in	8 in or more
Overlay on sound pavement	1.5–2 in	Existing surface
Small parking lot	3–4 in, often in two lifts	6–10 in

These are common practice ranges, not rules. Soil type, drainage, and climate all change the right answer, so take a local paving contractor’s recommendation seriously. The asphalt thickness calculator explores the trade-offs.

How to measure for asphalt

• Measure the finished paved area, not the excavated area. Base gravel may extend wider, but asphalt stops at the edge line.
• Split flared aprons. Treat the straight run as one rectangle and the flare at the street as a second shape, then add the tons.
• Use compacted thickness. If the plan calls for “3 inches compacted,” enter 3. Crews lay it about 25% thicker and roll it down.
• Check curves. For a curved driveway, measure along the centerline for length and take the average width.

Mistakes that cost money

• Entering depth in feet. The depth box takes inches. Typing 0.25 because you were thinking “a quarter foot” would price a layer a quarter of an inch thick.
• Forgetting the base. Asphalt laid on poor soil cracks no matter how thick it is. Order the aggregate base separately with the gravel base calculator.
• Ordering too tight. Hot mix cannot be stored once it cools. A short load means a cold joint in the middle of the drive, which is why the 10% box exists.
• Comparing quotes by area only. Two contractors quoting the same square footage may be pricing different thicknesses. Ask for tons and inches in writing.

For a full installed price including labor, use the asphalt driveway cost calculator. For patches and overlays, the asphalt tonnage calculator defaults to a thinner layer.