How Much Road Base for a 16x20 Parking Pad?
How much road base for a 16x20 parking pad is a quick volume problem. 320 square feet at 4 inches comes to 3.95 cubic yards. Road base usually weighs about 1.4 to 1.65 compacted tons per cubic yard, so plan on roughly 5.9 tons.
Volume and tonnage calculator →The math for a 16x20 parking pad
- Area: 16 × 20 = 320 sq ft.
- Depth in feet: 4 ÷ 12 = 0.333 ft.
- Cubic feet: 320 × 0.333 = 106.7 cu ft.
- Cubic yards: ÷ 27 = 3.95 yd³.
- Tons: × 1.5 = 5.9 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 | 3.95 | 5.9 | 6.5 |
| 6 in | 5.93 | 8.9 | 9.8 |
| 8 in | 7.90 | 11.9 | 13.0 |
About road base
Road base is meant to be compacted at close to the right moisture. Dry base rock does not lock up well; a light spray of water before rolling helps. 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. For parked vehicles, 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. 6.5 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 road base fits
Best suited to:
- 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 12x24 area at 4 inches takes about 5.3 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.
- Forgetting that compaction shrinks loose material. A loose 4-inch spread of a dense-graded stone may finish closer to 3 inches after rolling.
- Ordering exactly the math. Uneven ground and spillage nearly always need a little more than the flat calculation.
- Ignoring the base. A thin surface layer over soft soil fails early no matter how much material is on top.
Questions people ask
How many tons of road base for a 16x20 parking pad?
About 5.9 tons at 4 inches deep, or 6.5 tons with 10 percent extra.
How many cubic yards is a 16x20 parking pad at 4 inches?
About 3.95 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 16x20?
320 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 14x40 Parking Pad?
- How Much Road Base for a 14x50 Parking Pad?
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