Asphalt Calculator
By Taro Schenker | Updated February 11, 2026
Quick Answer: To calculate asphalt, multiply Length (ft) x Width (ft) x Thickness (in) / 12 / 27 to get cubic yards, then multiply by density and divide by 2,000 for tons. Hot mix asphalt weighs 3,960 lbs/cu yd (~2 tons). Cold patch weighs 3,500 lbs/cu yd. One ton of hot mix covers about 80 sq ft at 2 inches thick. Add 10% for waste. A 20 x 20 ft driveway at 2 inches thick needs about 1.48 cubic yards or 2.93 tons.
Calculate how much asphalt you need for your driveway, parking lot, or road project. Enter your dimensions and thickness to get the exact volume in cubic yards, weight in tons, and estimated material cost.
How to Calculate Asphalt
The formula for calculating asphalt volume and weight is:
- Measure the length and width of your paving area in feet.
- Determine your asphalt thickness (2-3 inches for driveways, 3-4 inches for parking lots).
- Multiply length × width to get the area in square feet.
- Multiply the area by the thickness (converted to feet) to get the volume in cubic feet.
- Divide by 27 to convert to cubic yards, then multiply by the asphalt density to get the weight.
- Add 10% for waste and compaction variability.
Asphalt Thickness Guide
Recommended asphalt thickness varies by application and expected traffic load:
| Application | Recommended Thickness | Gravel Base |
|---|---|---|
| Residential Driveway | 2-3 inches | 6-8 inches |
| Parking Lot | 3-4 inches | 8-12 inches |
| Road / Heavy Traffic | 4-6 inches | 12-18 inches |
| Overlay / Resurfacing | 1.5-2 inches | Existing surface |
Hot Mix vs Cold Patch
Hot mix asphalt is the industry standard for paving driveways, parking lots, and roads. It is produced at a plant where aggregate and liquid asphalt binder are heated to 300-350°F and combined. It must be transported and laid while hot, which means you need professional equipment and crew. Hot mix compacts tightly, creating a smooth and durable surface that lasts 15-20 years with proper maintenance.
Cold patch asphalt is a pre-mixed product available in bags at hardware stores. It can be applied at any temperature, making it ideal for emergency pothole repairs and small patches. However, cold patch is a temporary fix for most applications. It does not compact as densely as hot mix, is more susceptible to cracking, and typically lasts 1-3 years. Use cold patch for spot repairs, not for full paving projects.
Tips for Asphalt Projects
- Sub-base preparation: A properly graded and compacted gravel base is essential. Poor sub-base preparation is the leading cause of asphalt failure and cracking.
- Temperature matters: Only pave when air temperatures are above 50°F. Asphalt cools quickly in cold weather and will not compact properly.
- Compaction: Asphalt must be rolled with a heavy roller while still hot. Each pass increases density and durability. Proper compaction reduces the volume by about 25% from loose material.
- Drainage: Ensure your paved surface has a slight slope (1-2% grade) to direct water away. Standing water accelerates asphalt deterioration.
- Sealcoating: Apply a sealcoat every 2-3 years to protect against UV damage, water penetration, and oil stains. This extends the lifespan of your asphalt significantly.
Formula Summary
Asphalt Volume Formula: To calculate the cubic yardage of asphalt needed, multiply the Length (ft) x Width (ft) x Thickness (in), divide by 12 to convert thickness to feet, then divide by 27 to convert cubic feet to cubic yards.
$$V_{\text{cu yd}} = \frac{L_{\text{ft}} \times W_{\text{ft}} \times T_{\text{in}}}{12 \times 27}$$
Weight Formula: $$W_{\text{tons}} = \frac{V_{\text{cu yd}} \times \rho}{2000}$$ where $\rho$ is the asphalt density in lbs/cu yd.
Cost Formula: $$\text{Cost} = W_{\text{tons}} \times \text{Price per ton}$$
| Asphalt Type | Density (lbs/cu yd) |
|---|---|
| Hot Mix (Standard) | 3,960 |
| Cold Patch | 3,500 |
Standard Assumptions: Waste factor of 10% accounts for compaction variability, uneven sub-grade, and material waste. 1 cubic yard = 27 cubic feet. 1 ton = 2,000 lbs. Asphalt is sold by the ton. Hot mix must be laid at 300-350 degrees F.
Related Calculators
- Gravel Calculator — calculate gravel for driveways, paths, and sub-base
- Concrete Calculator — estimate concrete for slabs, footings, and foundations
- Cubic Yard Calculator — convert any dimensions to cubic yards
Estimates are for planning purposes only. Consult a qualified contractor for critical projects. Actual material requirements may vary based on site conditions, waste, and installation methods.
Pricing last verified: February 2026. Material prices vary by region, season, and supplier. Prices shown are national averages for planning purposes.