How this calculator works
Area × compacted thickness (in feet) × density gives pounds; ÷ 2,000 gives US tons, plus your waste allowance. The presets fill in a starting thickness and waste for a driveway (3 in, 5%), parking lot (4 in, 7%) or overlay (2 in, 5%). Density takes lb/ft³ or kg/m³, or switch to Spread Rate for a lb/yd² per inch figure. Add a price per ton for the material cost, or use Known weight to convert a weigh ticket in pounds. For irregular shapes, total the area first with the asphalt square footage calculator.
The formula
Example: 500 sq ft × (2 in ÷ 12) × 145 lb/ft³ ÷ 2,000 = 6.04 tons. A spread rate of about 110 lb/yd²/in is the same material written per square yard — 9 sq ft × (1 in ÷ 12) × 145 lb/ft³ = 109 lb — so the two methods agree.
Worked examples
Example 1 — Driveway preset: 20 ft × 50 ft at 3 inches
- Area:
- 20 ft × 50 ft = 1,000 sq ft
- Preset:
- 3 in compacted, 5% waste
- Mix density:
- 145 lb/ft³
- Volume: 1,000 sq ft × (3 in ÷ 12) = 250 cu ft
- Weight: 250 cu ft × 145 lb/ft³ = 36,250 lb
- Convert to tons: 36,250 lb ÷ 2,000 = 18.13 tons
- Add 5% waste: 18.13 × 1.05 = 19.03 tons
Order about: 19 US tons
Example 2 — Parking-lot preset: 100 ft × 100 ft at 4 inches
- Area:
- 100 ft × 100 ft = 10,000 sq ft
- Preset:
- 4 in compacted, 7% waste
- Mix density:
- 145 lb/ft³
- Volume: 10,000 sq ft × (4 in ÷ 12) = 3,333 cu ft
- Weight: 3,333 cu ft × 145 lb/ft³ = 483,333 lb
- Convert to tons: 483,333 lb ÷ 2,000 = 241.67 tons
- Add 7% waste: 241.67 × 1.07 = 258.58 tons
Order about: 259 US tons
Subtract landscaped islands first; many islands and curbs push waste toward 10%.
Example 3 — Overlay preset: 2,000 sq ft at 2 inches
- Total area:
- 2,000 sq ft
- Preset:
- 2 in compacted, 5% waste
- Mix density:
- 145 lb/ft³
- Volume: 2,000 sq ft × (2 in ÷ 12) = 333.3 cu ft
- Weight: 333.3 cu ft × 145 lb/ft³ = 48,333 lb
- Convert to tons: 48,333 lb ÷ 2,000 = 24.17 tons
- Add 5% waste: 24.17 × 1.05 = 25.38 tons
Order about: 25.4 US tons
The tack coat that bonds new to old is ordered separately.
Example 4 — Known weight: a 27,500 lb plant weigh ticket
- Ticket weight:
- 27,500 lb
- Mix density:
- 145 lb/ft³
- To short tons: 27,500 lb ÷ 2,000 = 13.75 tons
- To metric tonnes: 27,500 lb ÷ 2,204.62 = 12.47 t
- To volume: 27,500 lb ÷ 145 lb/ft³ = 189.7 cu ft = 7.02 cu yd
Load weight: 13.75 US tons (12.47 t)
Against a 14-ton order this is a normal short delivery, not an error.
Units & density reference
These are exact unit definitions, so no density is involved: the pound is 0.45359237 kg and the inch 25.4 mm (NIST SP 811). A UK long ton is 2,240 lb, so confirm which ton a supplier means. Example: a supplier's 2,350 kg/m³ ÷ 16.0185 = 146.7 lb/ft³, inside the 142–148 lb/ft³ range.
Hot mix asphalt density and the weight of one cubic yard
| Density (lb/ft³) | Density (kg/m³) | 1 cu yd weighs | Note |
|---|---|---|---|
| 142 lb/ft³ | 2,275 kg/m³ | 3,834 lb (1.92 tons) | Low end of the in-place range |
| 145 lb/ft³ | 2,323 kg/m³ | 3,915 lb (1.96 tons) | OtherCalculators default |
| 148 lb/ft³ | 2,371 kg/m³ | 3,996 lb (2.00 tons) | Asphalt Institute “Use 148 PCF” |
Thickness guide: units and asphalt per 1,000 sq ft (145 lb/ft³, before waste)
| Compacted thickness | Feet | Centimeters | Volume (cu yd) | Weight (US tons) |
|---|---|---|---|---|
| 1.5 in | 0.1250 ft | 3.81 cm | 4.63 cu yd | 9.06 tons |
| 2 in | 0.1667 ft | 5.08 cm | 6.17 cu yd | 12.08 tons |
| 2.5 in | 0.2083 ft | 6.35 cm | 7.72 cu yd | 15.10 tons |
| 3 in | 0.2500 ft | 7.62 cm | 9.26 cu yd | 18.13 tons |
| 4 in | 0.3333 ft | 10.16 cm | 12.35 cu yd | 24.17 tons |
| 5 in | 0.4167 ft | 12.70 cm | 15.43 cu yd | 30.21 tons |
| 6 in | 0.5000 ft | 15.24 cm | 18.52 cu yd | 36.25 tons |
Minimum single-lift thickness by nominal maximum aggregate size
| Nominal max aggregate size | 3 × NMAS | Practical minimum lift |
|---|---|---|
| 9.5 mm (⅜ in) | 28.5 mm = 1.12 in | 1.5 in |
| 12.5 mm (½ in) | 37.5 mm = 1.48 in | 1.5 in |
| 19.0 mm (¾ in) | 57.0 mm = 2.24 in | 2.5 in |
| 25.0 mm (1 in) | 75.0 mm = 2.95 in | 3 in |
Key facts
- Asphalt tonnage equals area in square feet times thickness in feet times density in pounds per cubic foot, divided by 2,000.
- At 145 lb/ft³, one inch of compacted asphalt weighs about 12.1 lb per square foot, or about 6 US tons per 1,000 square feet.
- The Asphalt Institute gives in-place asphalt mixture unit weight as 142–148 lb/ft³; 145 lb/ft³ equals about 2,323 kg/m³.
- One cubic yard of compacted asphalt weighs about 3,915 lb, or 1.96 US tons, at 145 lb/ft³.
Who should use this and when
Homeowners use it to size a driveway or resurfacing job and sense-check a quote; estimators use it for takeoffs on lots and overlays; buyers use Known weight to reconcile weigh tickets in pounds against an order in tons. If you have a volume in cubic yards, the asphalt tons to cubic yards calculator converts it straight to tons; to budget labor as well as material, use the asphalt driveway cost calculator.
Tips and common pitfalls
- Convert thickness to feet before multiplying. Multiplying square feet by inches overstates the answer twelvefold — the most common tonnage error.
- Use compacted thickness, not loose depth. Mix is laid loose and rolled down; order against the finished design thickness.
- Repair before an overlay. An overlay renews the surface, not a failed base: fill potholes and deep cracks first or they reflect through the new layer.
- Add waste before you order, not after. A 5–10% buffer on the calculated tonnage covers compaction and edges; rounding up to the load minimum is separate.
Frequently Asked Questions
What is the formula for asphalt tonnage?
Tonnage = area (sq ft) × thickness (ft) × density (lb/ft³) ÷ 2,000. Thickness must be in feet, so divide inches by 12 first. Using 145 lb/ft³ for density: a 500 sq ft area at 2 inches is 500 × 0.167 × 145 ÷ 2,000 = 6.04 tons.
How thick should asphalt be for a driveway, parking lot or overlay?
Common practice is 2–3 inches of compacted asphalt for a residential driveway, 3–4 inches for a car parking lot, 4–6 inches where loaded trucks run, and 1.5–2 inches for an overlay on a sound surface. These are common-practice ranges, not a standard: your local code or the project specification governs.
How much waste should I add to an asphalt tonnage order?
A 5–10% allowance is typical, covering compaction, uneven subgrade, and material lost at edges and joints. Large, simple rectangles sit near 5%; small jobs and parking lots with islands, curbs and irregular edges run closer to 10%. This is a planning convention, not a fixed rule — confirm with your paver.
What density should I use for asphalt, and how do I convert it to kg/m³?
Use 145 lb/ft³ unless your supplier gives a mix figure. It sits inside the Asphalt Institute's 142–148 lb/ft³ in-place range, and the Institute suggests 148 for calculations. Multiply lb/ft³ by 16.0185 for kg/m³, so 145 lb/ft³ is about 2,323 kg/m³; divide by 16.0185 to go back.
How many pounds are in a ton of asphalt?
A US short ton is exactly 2,000 pounds, so pounds ÷ 2,000 gives tons. A metric tonne is 1,000 kg, about 2,204.62 lb, and a UK long ton is 2,240 lb, so confirm which ton a supplier or weigh ticket means. No density is involved: it is one weight in different units.
How do I work out the material cost from the tonnage?
Multiply the order tonnage, including waste, by your plant's current price per ton; enter the price above and the calculator does it. A per-ton price usually covers material at the plant only. Labor, hauling, site prep and installation are quoted separately, and prices move with crude oil, haul distance and mix type.
More asphalt calculators
Estimates & Assumptions
- Tonnage is computed as area × (thickness ÷ 12) × density ÷ 2,000, in US short tons of 2,000 lb.
- The 145 lb/ft³ default is a planning convention inside the Asphalt Institute's 142–148 lb/ft³ in-place range. Ask your supplier for your specific mix density.
- Project-type presets are common-practice starting points (driveway 3 in, parking lot 4 in, overlay 2 in), not a standard. Your local code or the project specification governs.
- Material cost is order tons × the price you enter. It excludes labor, hauling, the aggregate base, the tack coat and installation; this tool does not perform pavement structural design.
Estimates are for planning only. Confirm quantities and mix density against the project specification before ordering material.