Whether you are paving a residential driveway, resurfacing a car park, or patching a utility trench, ordering the right amount of hot-mix asphalt (HMA) requires converting your surface dimensions (length × width × compacted thickness) into tons (or metric tonnes). Under-ordering leaves cold seams while waiting for a second truck; over-ordering leaves you paying disposal fees for hardened mix.
The Chippy Tools Asphalt Calculator handles both imperial (feet, inches, cubic yards, US tons) and metric (metres, millimetres, cubic metres, tonnes) measurements offline on iOS and Android, including custom material density and waste allowances.
Quick Reference Table: Asphalt Tonnage by Driveway Size & Thickness
The table below uses the industry-standard compacted hot-mix asphalt density of 145 lbs/ft³ (2,320 kg/m³) and includes both net tonnage and recommended order quantity (+10% allowance) for sub-grade variations:
| Project / Driveway Size | Area | 2" Thick (Net / +10%) | 3" Thick (Net / +10%) | 4" Thick (Net / +10%) | Metric Equivalent (at 75 mm / 3") |
|---|---|---|---|---|---|
| 10 × 20 ft (1-Car Pad) | 200 ft² (18.6 m²) | 2.42 t / 2.7 tons | 3.63 t / 4.0 tons | 4.83 t / 5.3 tons | 3.29 t / 3.6 tonnes |
| 12 × 30 ft (Single Driveway) | 360 ft² (33.4 m²) | 4.35 t / 4.8 tons | 6.53 t / 7.2 tons | 8.70 t / 9.6 tons | 5.92 t / 6.5 tonnes |
| 16 × 40 ft (Wide Single) | 640 ft² (59.5 m²) | 7.73 t / 8.5 tons | 11.60 t / 12.8 tons | 15.47 t / 17.0 tons | 10.52 t / 11.6 tonnes |
| 20 × 40 ft (2-Car Driveway) | 800 ft² (74.3 m²) | 9.67 t / 10.6 tons | 14.50 t / 16.0 tons | 19.33 t / 21.3 tons | 13.15 t / 14.5 tonnes |
| 20 × 60 ft (Long 2-Car) | 1,200 ft² (111.5 m²) | 14.50 t / 16.0 tons | 21.75 t / 23.9 tons | 29.00 t / 31.9 tons | 19.73 t / 21.7 tonnes |
| 24 × 50 ft (Double + Turn) | 1,200 ft² (111.5 m²) | 14.50 t / 16.0 tons | 21.75 t / 23.9 tons | 29.00 t / 31.9 tons | 19.73 t / 21.7 tonnes |
| 30 × 60 ft (Small Lot) | 1,800 ft² (167.2 m²) | 21.75 t / 23.9 tons | 32.63 t / 35.9 tons | 43.50 t / 47.9 tons | 29.60 t / 32.6 tonnes |
Coverage Chart: How Many Square Feet Does 1 Ton of Asphalt Cover?
Paving contractors often estimate hot-mix orders using the 110 lb per square yard per inch of thickness rule of thumb (which equals 146.7 lbs/ft³). Here is how much surface area 1 US short ton (2,000 lbs) and 1 metric tonne (1,000 kg) cover at common compacted depths:
| Compacted Thickness | Sq Ft Covered per 1 US Ton (2,000 lb) | US Tons Needed per 100 Sq Ft | m² Covered per 1 Metric Tonne (1,000 kg) |
|---|---|---|---|
| 1 inch (25 mm) — Overlay / Top Coat | 165 sq ft | 0.60 tons | 17.2 m² |
| 1.5 inches (38 mm) — Resurfacing Course | 110 sq ft | 0.91 tons | 11.3 m² |
| 2 inches (50 mm) — Light Driveway / Path | 82.5 sq ft | 1.21 tons | 8.6 m² |
| 3 inches (75 mm) — Standard Driveway | 55 sq ft | 1.81 tons | 5.7 m² |
| 4 inches (100 mm) — Heavy Driveway / Base | 41.2 sq ft | 2.42 tons | 4.3 m² |
| 6 inches (150 mm) — Commercial / Full-Depth | 27.5 sq ft | 3.63 tons | 2.9 m² |
How to Calculate Asphalt Tonnage by Hand (Formulas)
Imperial Formula (Feet, Inches & US Short Tons)
- Convert thickness from inches to feet:
Depth (ft) = Thickness (in) ÷ 12 - Calculate compacted volume in cubic feet:
Volume (ft³) = Length (ft) × Width (ft) × Depth (ft) - Multiply by asphalt density (145 lb/ft³) and divide by 2,000 lb/ton:
Asphalt (US Tons) = [Length (ft) × Width (ft) × (Thickness (in) ÷ 12) × 145] ÷ 2,000
- Add 5%–10% waste allowance: Multiply by
1.05(laser-graded base) or1.10(standard residential base).
Metric Formula (Metres, Millimetres & Metric Tonnes)
- Convert thickness from millimetres to metres:
Depth (m) = Thickness (mm) ÷ 1,000 - Calculate compacted volume in cubic metres:
Volume (m³) = Length (m) × Width (m) × Depth (m) - Multiply by compacted density (2.32 tonnes/m³ to 2.40 tonnes/m³):
Asphalt (Metric Tonnes) = Length (m) × Width (m) × (Thickness (mm) ÷ 1,000) × 2.32
Worked Examples
Example 1: Two-Car Residential Driveway (20 ft × 40 ft at 3 Inches Compacted)
Suppose you are paving a 20 ft wide by 40 ft long driveway with a 3-inch compacted hot-mix surface over a 6-inch compacted crushed aggregate base:
- Surface area:
20 ft × 40 ft = 800 sq ft - Compacted asphalt volume:
800 sq ft × (3 ÷ 12 ft) = 200 ft³(7.41 yd³) - Net asphalt weight:
200 ft³ × 145 lb/ft³ = 29,000 lbs= 14.50 US tons - Order quantity (+10% waste):
14.50 × 1.10= 15.95 tons (order 16 tons of hot-mix asphalt). - Screed depth on site: Because loose hot-mix compacts by roughly 20% to 25% under the vibratory roller, set your paver screed or rake guides to
3 in × 1.25= 3.75 inches (3-3/4 in) loose depth so it finishes at a true 3 inches after rolling. - Crushed stone base required (6 in deep):
800 sq ft × 0.5 ft ÷ 27 = 14.81 yd³ × 1.6 tons/yd³= 23.7 tons of crusher run / road base (see our Gravel Calculator).
Example 2: Metric Driveway (3.5 m × 15 m at 75 mm Compacted)
- Surface area:
3.5 m × 15 m = 52.5 m² - Compacted volume:
52.5 m² × 0.075 m = 3.9375 m³ - Net tonnage (at 2.35 t/m³):
3.9375 × 2.35= 9.25 tonnes - Order quantity (+10% allowance):
9.25 × 1.10= 10.18 tonnes (order 10.5 tonnes).
Asphalt Mix Types & Density Differences
Not all asphalt mixes weigh the same. If your batch plant specifies a mix design density, you can enter that exact figure in the Chippy Tools app:
| Mix Type | Typical Compacted Density | Common Use Case | Lift Thickness |
|---|---|---|---|
| Dense-Graded Surface Mix (9.5 mm / 12.5 mm) | 145 – 148 lb/ft³ (2,320 – 2,370 kg/m³) | Residential driveways, top wearing course, paths | 1.5 – 2.5 in (40 – 65 mm) |
| Binder / Base Course Mix (19 mm / 25 mm) | 148 – 152 lb/ft³ (2,370 – 2,435 kg/m³) | Structural lower layer under heavy driveways & parking lots | 2.5 – 4.0 in (65 – 100 mm) |
| Porous / Permeable Asphalt | 125 – 135 lb/ft³ (2,000 – 2,160 kg/m³) | Stormwater-draining car parks and eco-driveways | 3.0 – 4.0 in (75 – 100 mm) |
| Cold-Patch Asphalt (Bagged) | 130 – 138 lb/ft³ (2,080 – 2,210 kg/m³) | Pothole repairs and utility trench patching (50 lb / 20 kg bags) | 1.0 – 2.0 in per compacted lift |
Related Calculators for Paving & Site Prep
Preparing a driveway or parking area involves more than just the blacktop surface:
- Gravel Calculator: Estimate the compacted crushed stone or road-base sub-layer under your asphalt.
- Check Square Calculator: Pull 3-4-5 diagonals on formwork and parking bays before excavating.
- Dumpy Level Calculator: Check sub-grade levels and drainage fall across the driveway.
- Fall & Gradient Converter: Ensure your driveway has at least a 1% to 2% cross-slope (1/8 in to 1/4 in per foot) so water sheds cleanly.