How Much Road Base for a 18x70 Driveway?
How much road base for a 18x70 driveway: at 4 inches deep you need about 15.56 cubic yards, which is roughly 23.3 tons at 1.5 tons per yard. The driveway covers 1,260 square feet, so every inch of depth adds about 3.89 yards.
Volume and tonnage calculator →The math for a 18x70 driveway
- Area: 18 × 70 = 1,260 sq ft.
- Depth in feet: 4 ÷ 12 = 0.333 ft.
- Cubic feet: 1,260 × 0.333 = 420.0 cu ft.
- Cubic yards: ÷ 27 = 15.56 yd³.
- Tons: × 1.5 = 23.3 tons.
The volume and tonnage calculator does this for any size.
Road base needed by depth
| Depth | Cubic yards | Tons (approx.) | Tons +10% |
|---|---|---|---|
| 4 in | 15.56 | 23.3 | 25.7 |
| 6 in | 23.33 | 35.0 | 38.5 |
| 8 in | 31.11 | 46.7 | 51.3 |
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. Ask your supplier for their own tons-per-yard figure, since stone source and moisture shift it.
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. For car and truck traffic, the depths in the table above are a reasonable starting range.
Ordering tips
- Round up. Compaction and uneven ground eat material. Adding about 10 percent is common.
- Delivery size. 25.7 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.
Good and poor uses for road base
Good uses:
- 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 4 inches takes about 2.4 tons.
- Weight used here: about 1.5 tons per cubic yard.
Where estimates go wrong
- Using inches as if they were feet. Depth has to be divided by 12 before you multiply; skipping that step inflates the order twelvefold.
- Mixing up cubic yards and tons. Yards are volume, tons are weight; convert with the product’s weight per yard.
- Ignoring the base. A thin surface layer over soft soil fails early no matter how much material is on top.
- Measuring only the main rectangle. Aprons, turnouts and curved edges add real square footage.
Questions people ask
How many tons of road base for a 18x70 driveway?
About 23.3 tons at 4 inches deep, or 25.7 tons with 10 percent extra.
How many cubic yards is a 18x70 driveway at 4 inches?
About 15.56 cubic yards.
How much does a cubic yard of road base weigh?
Usually around 1.4 to 1.65 compacted tons, depending on stone size, fines and moisture.
How deep should road base be for a driveway?
The table above shows 4 to 8 inches. Shallower depths suit top dressing; deeper depths suit new installs and heavier use.
How many square feet is 18x70?
1,260 square feet.
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 a Ton of Gravel Cover? Depth Chart
- How Much Road Base for a 18x50 Driveway?
- How Much Road Base for a 18x60 Driveway?
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