How Much Gravel for a 12x20 Carport?
A 12 by 20 foot carport (single) covers 240 square feet. How much gravel for a 12x20 carport: plan on 6.2 tons for a 6-inch pad that will carry vehicles.
Volume and tonnage calculator →The math
- Area: 240.0 sq ft.
- Depth in feet: 4 ÷ 12 = 0.333 ft.
- Cubic yards: 240.0 × 0.333 ÷ 27 = 2.96 yd³.
- Tons: × about 1.4 tons per yard = 4.1 tons.
The gravel calculator does this for any size.
Related: How Much Crushed Stone for a 12x20 Carport?
Gravel needed by depth
| Depth | Cubic yards | Tons of gravel | Tons +10% |
|---|---|---|---|
| 4 in | 2.96 | 4.1 | 4.6 |
| 6 in | 4.44 | 6.2 | 6.8 |
| 8 in | 5.93 | 8.3 | 9.1 |
Carport pad tips
Metal carport kits anchor to concrete, asphalt or ground anchors in soil or gravel. Check your kit’s anchor type before building the pad, and extend the stone a foot past the frame so posts sit on compacted base.
Related: How Much Crusher Run for a 12x20 Carport?
How deep
Four inches works on firm ground for cars. Six inches is safer for trucks, heavy SUVs or soft soil.
Getting it delivered
Most quarries and landscape yards deliver by the ton; ask whether there is a minimum and a delivery fee, and where the driver can dump without damaging your lawn. Gravel is a broad label, so confirm whether the yard means crushed or rounded stone and whether it carries fines. The scale ticket is the real weight; tons per yard here is a planning figure.
Measuring the area
Use a long tape and measure each side twice. If the ground slopes, measure depth at the high and low ends and average them. Irregular outlines can be broken into simple rectangles, triangles and circles; add the pieces for the total square footage before converting to tons.
Common mistakes
The most frequent problem is ordering for the finished depth without allowing for compaction, which can shrink a loose layer by 10 to 20 percent. Another is skipping fabric on soft soil and watching the stone vanish into the mud over the first wet season. Spreading everything in one thick layer instead of compacted lifts also leaves a soft, rutted surface.
Questions people ask
How many tons of gravel for a 12x20 carport?
About 4.1 tons at 4 inches or 6.2 at 6 inches.
Can a carport sit on gravel?
Many metal carports anchor into compacted gravel with ground anchors; check your kit.
How many tons of gravel are in a cubic yard?
Roughly 1.4 tons for planning, but suppliers vary with stone size and moisture.
Should I put landscape fabric under the stone?
On soft or clay soil, a woven geotextile keeps stone from sinking into the dirt and makes the layer last longer.
Related guides
- How Much Does a Ton of Gravel Cover? Depth Chart
- Tons to Cubic Yards for Gravel: Conversion Chart
- Crushed Stone vs Gravel: Differences and Best Uses
- Geotextile Fabric for Driveways: Woven vs Nonwoven and How Much You Need
- Compacting a Driveway Gravel Base in Lifts
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