Asphalt Calculator
Calculate how many tons of hot mix asphalt (HMA) you need for your driveway or parking lot paving project.
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Asphalt Paving Measurement
Measure your driveway or parking lot. Standard residential asphalt driveways are typically paved at a depth of 2 to 3 inches over a compacted gravel base.
How to Use the Asphalt Calculator
Asphalt is almost exclusively sold by weight (tons), making volume-to-weight conversions critical for accurate ordering.
- Measure the paving area: Input the length and width of the driveway or parking lot in feet.
- Set the thickness: Input the desired compacted thickness in inches. (Usually 2-3 inches for residential).
- Get tonnage: The calculator instantly outputs the exact tons of hot mix asphalt required.
Asphalt Tonnage Formula
Because asphalt is so dense, the conversion factor is higher than for other materials.
Step 1: Find Volume
Volume (ft³) = Length (ft) × Width (ft) × (Thickness in inches ÷ 12)
Step 2: Convert to Tons
Tons = (Volume in ft³ × 145 lbs) ÷ 2000 lbs
Note: 145 lbs/ft³ is the standard industry estimate for compacted hot mix asphalt density.
Asphalt Example Calculation
You need to pave a 40-foot by 20-foot driveway with 2 inches of asphalt.
- Area: 40 × 20 = 800 square feet.
- Volume in ft³: 800 × (2/12) = 133.3 cubic feet.
- Math: (133.3 × 145) ÷ 2000 = 9.66 tons.
Conclusion: You will need to order approximately 9.7 tons of asphalt to complete the job.
Tips for Paving with Asphalt
- It's all about the base: Asphalt is flexible. If the gravel sub-base underneath it moves or settles, the asphalt will crack. Spend 90% of your effort ensuring a perfectly compacted gravel base.
- Temperature matters: Hot mix asphalt must be laid and compacted while it is still hot (typically between 275°F and 300°F). Do not attempt to pave on very cold days.
- Proper compaction: Use a heavy vibratory roller to compact the asphalt immediately after it is laid down. Proper compaction is what gives the surface its strength and longevity.
Frequently Asked Questions
How thick should an asphalt driveway be?
For a standard residential driveway with a good gravel sub-base, a 2 to 3 inch layer of compacted asphalt is sufficient. If heavy vehicles (like RVs or large trucks) will be parked on it, 4 inches is recommended.
How much does a ton of asphalt cover?
At a standard compacted thickness of 2 inches, one ton of hot mix asphalt will cover approximately 80 square feet.
What is the density of hot mix asphalt?
Hot mix asphalt (HMA) is very dense, weighing approximately 145 pounds per cubic foot. This makes it significantly heavier than concrete or gravel per unit of volume.
Can I install asphalt over an existing concrete driveway?
Yes, this is called an asphalt overlay. However, any cracks or joints in the concrete will eventually 'reflect' through the new asphalt. The concrete must also be stable and not heavily degraded.