How Much Road Base for a 18x50 Parking Pad?
How much road base for a 18x50 parking pad: at 4 inches deep you need about 11.11 cubic yards, which is roughly 16.7 tons at 1.5 tons per yard. The parking pad covers 900 square feet, so every inch of depth adds about 2.78 yards.
Volume and tonnage calculator →The math for a 18x50 parking pad
- Area: 18 × 50 = 900 sq ft.
- Depth in feet: 4 ÷ 12 = 0.333 ft.
- Cubic feet: 900 × 0.333 = 300.0 cu ft.
- Cubic yards: ÷ 27 = 11.11 yd³.
- Tons: × 1.5 = 16.7 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 | 11.11 | 16.7 | 18.3 |
| 6 in | 16.67 | 25.0 | 27.5 |
| 8 in | 22.22 | 33.3 | 36.7 |
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 per yard is a planning number; the scale ticket at the yard is the real one.
Preparing the parking pad
Dig out organic soil, compact the subgrade and set an edge so the stone does not migrate onto the lawn. A pad that holds parked weight for long periods benefits from a dense base under the surface stone. Since the parking pad carries parked vehicles, 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. 18.3 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 parking pad as firm ground allows.
Good and poor uses for road base
Best suited to:
- Base under asphalt and concrete
- Gravel roads and drives
- Equipment and shed pads
Less suited to:
- 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 10x20 area at 3 inches takes about 2.8 tons.
- Weight used here: about 1.5 tons per cubic yard.
Where estimates go wrong
- 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.
- 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.
Questions people ask
How many tons of road base for a 18x50 parking pad?
About 16.7 tons at 4 inches deep, or 18.3 tons with 10 percent extra.
How many cubic yards is a 18x50 parking pad at 4 inches?
About 11.11 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 parking pad?
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 18x50?
900 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 18x36 Parking Pad?
- How Much Road Base for a 18x40 Parking Pad?
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