How Much Does 18 Tons of Road Base Cover?
How much does 18 tons of road base cover depends on how deep you spread it. At about 1.5 tons per cubic yard, 18 tons is roughly 12.0 cubic yards. Spread 6 inches deep, that covers about 648 square feet. Every added inch of depth cuts the coverage noticeably.
Volume and tonnage calculator →How the coverage is figured
- Tons to cubic yards: 18 ÷ 1.5 = 12.0 yd³.
- Cubic yards to cubic feet: × 27 = 324 cu ft.
- Divide by depth in feet: at 6 inches (0.500 ft), 324 ÷ 0.500 = 648 sq ft.
Coverage of 18 tons at different depths
| Depth | Square feet covered | Square yards |
|---|---|---|
| 4 in | 972 | 108 |
| 6 in | 648 | 72 |
| 8 in | 486 | 54 |
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.
What 18 tons looks like on site
18 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.
Where road base fits
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
- Assuming every supplier uses the same weight. Two yards selling the same product name can quote different tons per yard.
- Mixing up cubic yards and tons. Yards are volume, tons are weight; convert with the product’s weight per yard.
- Forgetting that compaction shrinks loose material. A loose 4-inch spread of a dense-graded stone may finish closer to 3 inches after rolling.
- Skipping drainage. Water sitting under any surface softens the base and leads to ruts and potholes.
Questions people ask
How many cubic yards is 18 tons of road base?
About 12.0 cubic yards at 1.5 tons per yard.
How many square feet does 18 tons of road base cover at 6 inches?
About 648 square feet.
How many square feet does 18 tons cover at 4 inches?
About 972 square feet.
How much does a yard of road base weigh?
About 1.4 to 1.65 compacted tons.
Will 18 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
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