How Much Does 40 Tons of Road Base Cover?
How much does 40 tons of road base cover depends on how deep you spread it. At about 1.5 tons per cubic yard, 40 tons is roughly 26.7 cubic yards. Spread 6 inches deep, that covers about 1,440 square feet. Every added inch of depth cuts the coverage noticeably.
Volume and tonnage calculator →How the coverage is figured
- Tons to cubic yards: 40 ÷ 1.5 = 26.7 yd³.
- Cubic yards to cubic feet: × 27 = 720 cu ft.
- Divide by depth in feet: at 6 inches (0.500 ft), 720 ÷ 0.500 = 1,440 sq ft.
Coverage of 40 tons at different depths
| Depth | Square feet covered | Square yards |
|---|---|---|
| 4 in | 2,160 | 240 |
| 6 in | 1,440 | 160 |
| 8 in | 1,080 | 120 |
About road base
Road base (also called base rock, ABC, or Class 2 base in different states) is a graded mix of stone and fines made to compact into a load-bearing layer. Weight runs about 1.4 to 1.65 compacted tons per cubic yard, so treat the table as a planning range rather than an exact figure.
Putting 40 tons to use
40 tons will usually take two or more truck loads, though legal limits vary by truck and state. Spread from the pile with a loader, skid steer or wheelbarrow, then rake to depth before compacting if the material calls for it.
- Check depth as you go. Stakes marked at the target depth help keep the spread even.
- Expect some loss. Compaction and uneven ground use more than the flat-math figure. Keep about 10 percent in reserve.
- Ask about moisture. Wet material weighs more, so a ton of it covers less.
To run your own numbers, use the volume and tonnage calculator.
Good and poor uses for road base
Works well for:
- Base under asphalt and concrete
- Gravel roads and drives
- Equipment and shed pads
Think twice for:
- Drainage layers
- Decorative surfaces
- Surfaces that will stay uncompacted
Quick reference numbers
- Per inch over 100 sq ft: about 0.46 tons of road base (0.31 cubic yards).
- Per inch over 1,000 sq ft: about 4.6 tons.
- Another size for comparison: a 8x16 area at 2 inches takes about 1.2 tons.
- Weight used here: about 1.5 tons per cubic yard.
Mistakes that throw off the order
- Ordering exactly the math. Uneven ground and spillage nearly always need a little more than the flat calculation.
- Skipping drainage. Water sitting under any surface softens the base and leads to ruts and potholes.
- Assuming every supplier uses the same weight. Two yards selling the same product name can quote different tons per yard.
- Measuring only the main rectangle. Aprons, turnouts and curved edges add real square footage.
Questions people ask
How many cubic yards is 40 tons of road base?
About 26.7 cubic yards at 1.5 tons per yard.
How many square feet does 40 tons of road base cover at 6 inches?
About 1,440 square feet.
How many square feet does 40 tons cover at 4 inches?
About 2,160 square feet.
How much does a yard of road base weigh?
About 1.4 to 1.65 compacted tons.
Will 40 tons fit in one truck?
It depends on the truck. Single-axle dump trucks often carry under 10 tons and tandems around 13 to 16; your supplier will know their limits.
Related guides
- Crushed Stone vs Gravel: Differences and Best Uses
- Tons to Cubic Yards for Gravel: Conversion Chart
- How Many Tons of Gravel in a Dump Truck? Loads and Coverage
- How Much Does 30 Tons of Road Base Cover?
- How Much Does 35 Tons of Road Base Cover?
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