Asphalt / Paving Calculator

Asphalt is ordered by the ton and laid by the square foot, and the bridge between the two is density. A driveway looks like a thin sheet of blacktop, but a 500 square-foot pad three inches deep swallows nine tons of hot mix, and underneath it hides a crushed-stone base nearly as heavy again. Get the tonnage wrong and either the paver stops halfway down the driveway or you pay for a load that sits in the yard.

Asphalt Paving Calculator converts your area and thickness into the tonnes of hot-mix asphalt and aggregate base you actually need, for driveways, paths, roads and parking lots. It models the surface course and the base course separately, applies the compacted density of hot mix, converts between imperial and metric, and folds in a price per ton so the report is an order you can read to a plant.

The learning guide explains the base-course-versus-surface-course question, what compaction means for your order, and why density is the number on the truck scale. Everything runs in your browser — nothing is uploaded.

• Two-layer model: Surface asphalt course and compacted aggregate base estimated together, the way a real paving spec is built.
• Thickness presets: 2, 3, 4-inch surface with a linked base, or custom thicknesses in inches or millimetres.
• Hot-mix density: Default 145 lb/cu ft (2,320 kg/m³) with override for your plant's mix design.
• Metric or imperial: Feet/inches or metres/millimetres with tons, tonnes, square feet, square metres, cubic yards and cubic metres all reported.
• Waste & edges: 5–10% allowance for curves, cold edges and patches, adjustable to your layout.
• Cost estimate: Price per ton for asphalt and base builds a paving budget alongside the tonnage.
• Live estimate: Tons of asphalt and base update as you type, with the density conversion shown step by step.
• Export: Copy or download the full paving report as text, CSV or JSON.
• Learning guide: Course-by-course explanation, thickness tables, compaction notes and paving tips built in.

1. Choose the unit system. Feet and inches for US tonnage, or metres and millimetres for metric tonnes.
2. Enter the paved area. Length and width for a rectangle; for odd shapes, break into rectangles and add the totals.
3. Set the surface thickness. 3 inches (75 mm) is standard for driveways; 2 for light paths, 4+ for heavier traffic.
4. Set the base thickness. 4–6 inches of compacted aggregate under the asphalt, deeper on poor soil.
5. Pick the density. Leave 145 lb/cu ft for standard hot mix or enter the plant's figure.
6. Add waste. 7 percent covers edges, curves and cold patches.
7. Enter prices (optional). Per ton for asphalt and per ton for base to build the budget.
8. Read the estimate. Asphalt tons, base tons and area appear instantly with costs.
9. Review the working. The maths shows volume × density ÷ 2,000 for each course.
10. Export the report. Copy or download as text, CSV or JSON to send to the plant.

Example 1 — Driveway. A 40×12 ft driveway, 3 in of asphalt over 5 in of base: asphalt = 40×12×0.25×145 ÷ 2000 ≈ 8.7 tons; base = 40×12×(5/12)×115 ÷ 2000 ≈ 11.5 tons of crushed stone.

Example 2 — Parking area. A 50-stall lot, 15,000 sq ft, 3 in asphalt: 15,000×0.25×145 ÷ 2000 ≈ 272 tons of hot mix, plus ~190 tons of 6-inch base.

Example 3 — Path metric. A 40 m × 1.5 m path at 40 mm asphalt (2,320 kg/m³): 40×1.5×0.04×2320 = 5,568 kg ≈ 5.6 tonnes, plus 100 mm base ≈ 14 tonnes of stone.

Example 4 — Resurface. A 600 sq ft driveway needing a 2-inch overlay: 600×(2/12)×145 ÷ 2000 ≈ 7.3 tons with no base work required.

Example 5 — Checking a quote. A contractor quotes 10 tons of asphalt for a 9.1-ton job with waste. The calculator says 8.7 + 7% ≈ 9.3 tons — the quote includes the allowance and is fair, and now you know the split.

• Order the tonnage that fits: Surface and base in one bill so the plant and the gravel pit both get the right numbers.
• Density, not guesswork: The hot-mix weight per cubic foot is built in and adjustable to your mix.
• Both courses visible: The base-under-asphalt logic that stops potholes is sized, not assumed.
• Metric or imperial: Tons or tonnes, yards or metres — the report speaks the plant's language.
• Budget without surprises: Price per ton turns volume into a number you can sign.
• Explainable maths: Area → volume → density → tons, with the conversion shown for both layers.
• Export-ready: Text, CSV and JSON reports drop into the purchase order.
• Free and private: No uploads, no accounts, no logging.