Complete guide to calculating asphalt quantities for any project
Calculating the right amount of asphalt for your project is crucial for accurate budgeting and planning. This comprehensive guide walks you through the process step-by-step with formulas and examples for calculating asphalt tonnage, volume, and cost.
Use our free asphalt calculator to instantly get precise measurements for your project.
Measure the length and width of the area to be paved. For rectangular areas, multiply length by width.
Area = Length × Width
Example: 20m × 10m = 200m²
Break down into simple geometric shapes (rectangles, triangles, circles), calculate area of each, then add them together.
Choose the appropriate thickness based on the intended use:
Convert thickness to the same unit system as your area measurement.
Feet = Inches ÷ 12
Meters = Millimeters ÷ 1000
Example: 3 inches = 0.25 feet
Example: 75mm = 0.075 meters
Multiply the area by the thickness to find the volume of asphalt needed.
Volume = Area × Thickness
Example: 200m² × 0.075m = 15m³
Example: 2,000ft² × 0.25ft = 500ft³
Multiply the volume by the density of asphalt. Hot mix asphalt typically has a density of:
Tonnes = Volume (m³) × 2.4
Example: 15m³ × 2.4 = 36 tonnes
Tons = Volume (ft³) × 150 ÷ 2000
Example: 500ft³ × 150 ÷ 2000 = 37.5 tons
Include a wastage factor of 5-10% to account for spillage, compaction, and irregular edges.
Total tonnage = Calculated tonnage × (1 + wastage %/100)
Example: 36 tonnes × (1 + 8/100) = 38.88 tonnes
Problem: Calculate the amount of asphalt needed for a driveway that is 40 feet long, 12 feet wide, with a thickness of 3 inches.
Problem: Calculate the amount of asphalt needed for a parking lot that is 30 meters long, 20 meters wide, with a thickness of 75mm.
| From | To | Multiply By |
|---|---|---|
| Square Feet | Square Yards | 0.111 |
| Square Feet | Square Meters | 0.093 |
| Square Yards | Square Meters | 0.836 |
| Square Meters | Square Feet | 10.764 |
| Square Meters | Square Yards | 1.196 |
| From | To | Multiply By |
|---|---|---|
| Inches | Feet | 0.0833 |
| Inches | Millimeters | 25.4 |
| Millimeters | Meters | 0.001 |
| Millimeters | Inches | 0.0394 |
| Centimeters | Inches | 0.3937 |
| Thickness | Coverage per Ton | Tons per 1000 ft² |
|---|---|---|
| 1 inch (25mm) | 160 ft² (15 m²) | 6.25 |
| 2 inches (50mm) | 80 ft² (7.5 m²) | 12.5 |
| 3 inches (75mm) | 53 ft² (5 m²) | 18.75 |
| 4 inches (100mm) | 40 ft² (3.7 m²) | 25 |
| 6 inches (150mm) | 27 ft² (2.5 m²) | 37.5 |
| From | To | Multiply By |
|---|---|---|
| Tons (US) | Tonnes (metric) | 0.907 |
| Tonnes (metric) | Tons (US) | 1.102 |
| Pounds | Kilograms | 0.454 |
| Kilograms | Pounds | 2.205 |
| Tons (US) | Pounds | 2000 |
| Tonnes (metric) | Kilograms | 1000 |
For more accurate and faster calculations, use our specialized asphalt calculators tailored to different project types:
Our comprehensive calculator for all asphalt projects. Enter dimensions, thickness, and density to get tonnage and cost.
Use CalculatorSpecialized for residential driveway projects with preset thickness options and cost estimates.
Use CalculatorTailored for commercial parking lots with options for traffic load factors and durability requirements.
Use CalculatorConvert between area, volume, and weight with precise density adjustments for different asphalt types.
Use CalculatorAccurate asphalt calculations are essential for proper budgeting, avoiding material shortages during installation (which can cause seam lines), and preventing excessive waste and unnecessary expenses. Ordering too little asphalt can delay your project and may result in visible seams where new asphalt meets partially cured asphalt.
Use these typical density values for different asphalt types:
Typically, add 5-10% for wastage. Use the lower end (5%) for simple, large rectangular areas, and the higher end (10%) for complex shapes with many edges, curves, or obstacles. For very intricate projects or those with difficult access, consider up to 15% wastage.
For irregular shapes:
For very complex shapes, consider using the grid method: draw a grid over your project area plan, count the number of complete squares, estimate partial squares, and multiply by the area of one square.
A ton (US short ton) equals 2,000 pounds, while a tonne (metric ton) equals 1,000 kilograms (approximately 2,204.6 pounds). When ordering asphalt, make sure you know which unit your supplier uses. In the US, suppliers typically quote in short tons, while in most other countries, they use metric tonnes.