Asphalt calculator: tons from area and thickness
This asphalt calculator converts the size of a driveway, car park or road into tons or tonnes of hot-mix asphalt. Enter the length and width (or the area you already know), the compacted thickness and the density, add a waste allowance, and it returns the weight, the volume and, if you enter a price, the cost.
It works as an asphalt calculator for square feet to tons in US units and as an asphalt calculator in metric with metres, millimetres and tonnes. The result is shown in both US tons (2,000 lb) and metric tonnes, so you can compare quotes that use either.
The maths runs in your browser. It estimates what to order; mix design, base preparation and compaction are the paving contractor's call.
How to use the Asphalt Calculator
- Choose feet and inches or metres and millimetres, then enter the length and width, or switch to “I know the area”.
- Enter the compacted thickness of the asphalt layer.
- Keep the 145 lb/ft³ (2,323 kg/m³) density or type the figure from your supplier.
- Add 5% or more for edges, slopes and truck waste, and optionally a price per ton or tonne.
- Read the tons or tonnes to order, the volume and the cost, then copy the summary.
Asphalt Calculator features
US and metric
US tons, tonnes, square feet, square yards, m² and m³ side by side.
Editable density
Starts at the common 145 lb/ft³ planning value and accepts your mix density.
Rule-of-thumb check
Shows the lb per square yard per inch figure that paving crews quote.
Price estimate
Cost from your price per ton or tonne in six currencies.
Area shortcut
Type a measured area for odd shapes.
How to calculate asphalt tonnage
Weight = area × compacted thickness × density. In US units, tons = area (ft²) × thickness (in) × density (lb/ft³) ÷ (12 × 2,000). Example: a 40 × 30 ft driveway is 1,200 ft². At 2 in thick that is 200 ft³, and at 145 lb/ft³ it weighs 29,000 lb, or 14.5 US tons (13.15 tonnes). Add 5% for waste and edges and the order becomes about 15.2 tons.
In metric, area (m²) × thickness (m) × 2,323 kg/m³ gives kilograms. A 100 m² area at 50 mm needs 5 m³ × 2,323 = 11.6 tonnes.
Paving crews often use about 110 lb per square yard for each inch of thickness. It follows from 145 lb/ft³ (145 × 9 ÷ 12 = 108.75 lb) rounded up, and the calculator prints the same figure for your density as a check.
Typical thickness and density
Density comes from the mix design and varies with aggregate, binder content and compaction (trade guides give about 143 to 148 lb/ft³, checked 19 October 2026). Ask the plant for its figure when you can.
| Use | Compacted thickness | Note |
|---|---|---|
| Residential driveway | 2 in (50 mm) | Over a compacted stone base |
| Heavy driveway or small car park | 3 in (75 mm) | Often laid in two lifts |
| Light road or commercial parking | 4 in (100 mm) | Binder and surface courses |
| Density (dense-graded hot mix) | 143 to 148 lb/ft³ | 2,290 to 2,370 kg/m³ compacted |
Ordering tips and limits
- Thickness is the compacted thickness. Loose mix is about 20 to 25% thicker before rolling, but suppliers quote tons of mix, so the calculator uses compacted density.
- Uneven bases soak up extra mix. Add 5 to 10% on old, rutted or sloped surfaces.
- The base stone is a separate order: use the gravel calculator for crushed stone and the excavation calculator for digging out. For concrete slabs see the concrete calculator.
- Sealcoating, tack coat, edging and delivery charges are not included.
Asphalt Calculator FAQ
How many tons of asphalt do I need for a driveway?
Multiply the area in square feet by the thickness in inches and by 145, then divide by 24,000. A 1,200 ft² driveway at 2 in needs 14.5 tons before waste.
How do I convert square feet to tons of asphalt?
Use tons = ft² × inches × 145 ÷ 24,000. For example 1,000 ft² at 3 in is 18.1 US tons. The asphalt calculator does the same and also shows tonnes.
How much does a ton of asphalt cover?
At 2 in thick and 145 lb/ft³ one US ton covers about 83 ft² (7.7 m²). At 3 in it covers about 55 ft².
What is the density of asphalt?
Compacted dense-graded hot mix is commonly planned at about 145 lb/ft³ (2,323 kg/m³), with real mixes around 143 to 148 lb/ft³. Use your supplier's figure when available.
How thick should an asphalt driveway be?
About 2 in (50 mm) compacted for cars, 3 in or more for heavier vehicles, over a well-compacted base. Your local contractor or council may set a minimum.
Does the asphalt calculator include the price?
Optionally. Enter your price per ton or tonne and it multiplies by the weight. It is an estimate; delivery, minimum loads and site work change real quotes.