How Much Asphalt Millings for a 20x40 Driveway?
How much asphalt millings for a 20x40 driveway is a quick volume problem. 800 square feet at 4 inches comes to 9.88 cubic yards. Asphalt millings usually weighs about 1.2 to 1.4 loose tons per cubic yard, so plan on roughly 12.8 tons.
Volume and tonnage calculator →The math for a 20x40 driveway
- Area: 20 × 40 = 800 sq ft.
- Depth in feet: 4 ÷ 12 = 0.333 ft.
- Cubic feet: 800 × 0.333 = 266.7 cu ft.
- Cubic yards: ÷ 27 = 9.88 yd³.
- Tons: × 1.3 = 12.8 tons.
The volume and tonnage calculator does this for any size.
Asphalt millings needed by depth
| Depth | Cubic yards | Tons (approx.) | Tons +10% |
|---|---|---|---|
| 3 in | 7.41 | 9.6 | 10.6 |
| 4 in | 9.88 | 12.8 | 14.1 |
| 6 in | 14.81 | 19.3 | 21.2 |
About asphalt millings
Millings vary by source: some loads are fine and uniform, others carry chunks. Ask the supplier for a screened product if you want a smoother finish, and check local rules, since some areas restrict their use near water. If the yard sells by the cubic yard instead of the ton, use the cubic-yard column directly.
Preparing the driveway
Strip sod and soft topsoil, grade for drainage and compact the subgrade before any stone goes down. Gravel drives last longer with a compacted base layer under the top stone and a slight crown so water runs off. Since the driveway carries car and truck traffic, a little extra depth is cheap insurance.
Ordering tips
- Round up. Compaction and uneven ground eat material. Adding about 10 percent is common.
- Delivery size. 14.1 tons may take more than one typical dump truck load; small loads may carry a delivery fee. See how many tons of gravel in a dump truck.
- Bulk vs bags. At this size bulk delivery is usually the practical choice.
- Where it drops. Have the truck dump as close to the driveway as firm ground allows.
When to choose asphalt millings
Works well for:
- Rural driveways and farm lanes
- Parking areas where a dust-free surface is wanted
- Low-cost base under a future paved surface
Think twice for:
- Areas near wells or streams where local rules limit them
- Decorative or barefoot areas
- Jobs needing a uniform, clean look
Quick reference numbers
- Per inch over 100 sq ft: about 0.40 tons of asphalt millings (0.31 cubic yards).
- Per inch over 1,000 sq ft: about 4.0 tons.
- Another size for comparison: a 8x16 area at 2 inches takes about 1.0 tons.
- Weight used here: about 1.3 tons per cubic yard.
Where estimates go wrong
- Ordering exactly the math. Uneven ground and spillage nearly always need a little more than the flat calculation.
- Forgetting that compaction shrinks loose material. A loose 4-inch spread of a dense-graded stone may finish closer to 3 inches after rolling.
- Measuring only the main rectangle. Aprons, turnouts and curved edges add real square footage.
- Assuming every supplier uses the same weight. Two yards selling the same product name can quote different tons per yard.
Questions people ask
How many tons of asphalt millings for a 20x40 driveway?
About 12.8 tons at 4 inches deep, or 14.1 tons with 10 percent extra.
How many cubic yards is a 20x40 driveway at 4 inches?
About 9.88 cubic yards.
How much does a cubic yard of asphalt millings weigh?
Usually around 1.2 to 1.4 loose tons, depending on stone size, fines and moisture.
How deep should asphalt millings be for a driveway?
The table above shows 3 to 6 inches. Shallower depths suit top dressing; deeper depths suit new installs and heavier use.
How many square feet is 20x40?
800 square feet.
Related guides
- How Many Tons of Asphalt Millings for a 40x25 Area?
- Tons to Cubic Yards for Gravel: Conversion Chart
- How Many Tons of Gravel in a Dump Truck? Loads and Coverage
- How Much Does a Ton of Gravel Cover? Depth Chart
- How Much Asphalt Millings for a 20x30 Driveway?
- How Much Asphalt Millings for a 20x35 Driveway?
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