How Much Gravel for a 18x20 Parking Pad?
A 18 by 20 foot parking pad is 360 square feet. How much gravel for a 18x20 parking pad depends on depth: at 4 inches it is about 4.44 cubic yards or 6.2 tons. Suppliers usually sell by the ton, so the tonnage is the number to give them.
Volume and tonnage calculator →The math for a 18x20 parking pad
- Area: 18 × 20 = 360 sq ft.
- Depth in feet: 4 ÷ 12 = 0.333 ft.
- Cubic feet: 360 × 0.333 = 120.0 cu ft.
- Cubic yards: ÷ 27 = 4.44 yd³.
- Tons: × 1.4 = 6.2 tons.
The volume and tonnage calculator does this for any size.
Gravel needed by depth
| Depth | Cubic yards | Tons (approx.) | Tons +10% |
|---|---|---|---|
| 2 in | 2.22 | 3.1 | 3.4 |
| 3 in | 3.33 | 4.7 | 5.1 |
| 4 in | 4.44 | 6.2 | 6.8 |
| 6 in | 6.67 | 9.3 | 10.3 |
About gravel
Because ’gravel’ covers so many products, the weight per yard moves with stone size and how much fine material is in the pile. Rounded stone with no fines rolls under tires; crushed stone with fines locks together. Ask your supplier for their own tons-per-yard figure, since stone source and moisture shift it.
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. 6.8 tons fits in a single 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.
Where gravel fits
Best suited to:
- Rural driveways and lanes where low upfront cost matters
- Drainage areas and around downspouts
- Temporary access while a site is under construction
Less suited to:
- Steep slopes, where loose stone washes downhill
- Spots plowed often, since plows push gravel into the lawn
- Areas next to doors, because stone tracks inside
Quick reference numbers
- Per inch over 100 sq ft: about 0.43 tons of gravel (0.31 cubic yards).
- Per inch over 1,000 sq ft: about 4.3 tons.
- Another size for comparison: a 10x20 area at 3 inches takes about 2.6 tons.
- Weight used here: about 1.4 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.
- Forgetting that compaction shrinks loose material. A loose 4-inch spread of a dense-graded stone may finish closer to 3 inches after rolling.
- Assuming every supplier uses the same weight. Two yards selling the same product name can quote different tons per yard.
- Skipping drainage. Water sitting under any surface softens the base and leads to ruts and potholes.
Questions people ask
How many tons of gravel for a 18x20 parking pad?
About 6.2 tons at 4 inches deep, or 6.8 tons with 10 percent extra.
How many cubic yards is a 18x20 parking pad at 4 inches?
About 4.44 cubic yards.
How much does a cubic yard of gravel weigh?
Usually around 1.3 to 1.5 tons, depending on stone size, fines and moisture.
How deep should gravel be for a parking pad?
The table above shows 2 to 6 inches. Shallower depths suit top dressing; deeper depths suit new installs and heavier use.
How many square feet is 18x20?
360 square feet.
Related guides
- How Much Does a Ton of Gravel Cover? Depth Chart
- Tons to Cubic Yards for Gravel: Conversion Chart
- How Many Tons of Gravel in a Dump Truck? Loads and Coverage
- How Much Gravel for a 16x40 Parking Pad?
- How Much Gravel for a 16x50 Parking Pad?
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