How Much Gravel Do You Need for a Driveway?
To find how much gravel for a driveway, multiply length (ft) by width (ft) by depth (ft), then divide by 27 for cubic yards. Multiply that by about 1.4 to get tons. A 20x20 driveway at 4 inches deep needs roughly 4.9 cubic yards, or about 6.9 tons.
Key Takeaways
- The formula: cubic yards = (length x width x depth in feet) / 27, then x 1.4 for tons.
- Most driveways run 4 to 6 inches deep, often a coarse base under a finer top stone.
- A standard 2-car driveway (24x20 ft) at 4 inches needs about 5.9 cubic yards, near 8.3 tons.
- Crushed stone, #57, and crusher run are the common driveway picks.
- Gravel weighs roughly 1.4 tons per cubic yard (USGS, construction aggregate reference).
What's the Formula for Driveway Gravel?
The formula is two quick steps. First, cubic yards = (length ft x width ft x depth ft) / 27. Then convert to weight: cubic yards x 1.4 gives you tons, since gravel runs about 1.4 tons per cubic yard (USGS construction aggregate data, 2023). That's it. Geometry first, then weight.
Depth is the part people get wrong. You measure depth in feet, not inches, so a 4-inch layer is 4 divided by 12, which equals 0.333 feet. A 6-inch layer is 0.5 feet. Plug that into the formula and the rest is arithmetic.
Why divide by 27? Because there are 27 cubic feet in a cubic yard. Gravel gets sold by the yard or the ton, never by the cubic foot, so the conversion matters. Want the weight side explained? See our guide on how to convert tons to cubic yards.
Cubic yards of gravel equal (length ft x width ft x depth ft) divided by 27. To get tons, multiply cubic yards by 1.4, the approximate density of construction gravel per cubic yard (USGS, 2023). A 4-inch depth equals 0.333 feet in the formula.
How Many Tons of Gravel for a 20x20 Driveway?
A 20x20 driveway at 4 inches deep needs about 4.9 cubic yards, or roughly 6.9 tons of gravel. Here's the math: 20 x 20 = 400 square feet. Multiply by 0.333 ft of depth and divide by 27, and you land at 4.94 cubic yards. Times 1.4 puts you near 6.9 tons.
We've found most folks order a touch over the calculated number. Gravel compacts as it settles, low spots eat more than you expect, and you don't want to stop a job to wait on a second load. Adding 5 to 10 percent is a fair cushion.
If you go deeper, the number climbs fast. That same 20x20 pad at 6 inches deep jumps to about 7.4 cubic yards, or near 10.4 tons. Depth is the single biggest driver of how much you'll buy.
A 20x20 gravel driveway at 4 inches deep requires about 4.9 cubic yards, equal to roughly 6.9 tons. The calculation: 400 square feet x 0.333 feet of depth, divided by 27, then multiplied by 1.4 tons per cubic yard for gravel weight.
How Much Gravel for a 2-Car Driveway?
A standard 2-car driveway, around 24 ft long by 20 ft wide, needs about 5.9 cubic yards at 4 inches deep, which works out to roughly 8.3 tons. Two cars side by side want at least 20 feet of width so doors open and you're not clipping mirrors. That 480-square-foot footprint is the common starting point.
Run it the same way. 24 x 20 = 480 square feet. Multiply by 0.333 ft, divide by 27, and you get 5.93 cubic yards. Times 1.4 gives about 8.3 tons. A wider 24x24 pad pushes that toward 7.1 cubic yards, near 10 tons.
Most "2-car driveway" numbers online assume the parking pad only. Real driveways include the approach strip from the road, and that strip is often longer than the pad itself. Measure the whole run, not just where the cars sit, or you'll come up short.
A 2-car driveway of roughly 24x20 feet at 4 inches deep needs about 5.9 cubic yards of gravel, equal to near 8.3 tons. The footprint covers 480 square feet, and 20 feet of width is the minimum for two vehicles to park side by side comfortably.
Driveway Gravel Coverage Table
The table below covers common driveway sizes at a 4-inch depth, the standard for most residential gravel driveways. Industry guidance from aggregate suppliers puts the typical surface course at 3 to 4 inches over a compacted base (Minnesota DOT aggregate base spec, 2022). Use it as a quick reference, then confirm against your real measurements.
| Driveway size (ft) | Square feet | Cubic yards (4 in) | Tons (4 in) |
|---|---|---|---|
| 10 x 10 | 100 | 1.2 | 1.7 |
| 12 x 20 | 240 | 3.0 | 4.1 |
| 16 x 20 | 320 | 4.0 | 5.5 |
| 20 x 20 | 400 | 4.9 | 6.9 |
| 24 x 20 (2-car) | 480 | 5.9 | 8.3 |
| 12 x 30 | 360 | 4.4 | 6.2 |
| 12 x 50 | 600 | 7.4 | 10.4 |
For a 6-inch depth, multiply the cubic-yard and ton figures by 1.5. Wondering how that load shows up? One delivery often arrives in a single truck. See how many cubic yards in a dump truck to picture it.
At a standard 4-inch depth, a 20x20 driveway needs 4.9 cubic yards (6.9 tons) and a 24x20 2-car driveway needs 5.9 cubic yards (8.3 tons). Typical residential surface course runs 3 to 4 inches over a compacted base (Minnesota DOT, 2022).
How Deep Should a Gravel Driveway Be?
A gravel driveway should be 4 to 6 inches deep total, and the better ones come in two layers. State aggregate specs commonly call for a compacted base course of 4 inches or more under the wearing surface (Minnesota DOT, 2022). Light foot and car traffic can sit at 4 inches. Trucks, RVs, or soft soil want 6 or more.
Base layer vs top layer
The base layer carries the load. It's usually a coarser, larger stone like crusher run that locks together and spreads weight onto the subgrade. Most builds run 3 to 4 inches of base, compacted before the next layer goes down.
The top layer is what you drive and walk on. It's a finer, cleaner stone that drains well and looks tidy. One to two inches of top course over a solid base gives you a surface that sheds water and holds up. Skip the base on soft ground and the driveway ruts within a season.
A gravel driveway should total 4 to 6 inches deep, ideally a 3-to-4-inch coarse base under a 1-to-2-inch finer top layer. State specs call for a compacted base course of 4 inches or more beneath the wearing surface (Minnesota DOT, 2022) for driveways carrying vehicle traffic.
Which Gravel Is Best for a Driveway?
The three common driveway picks are crusher run, #57 stone, and a crushed-stone top. Crusher run mixes stone and fines, so it compacts hard and makes a strong base. #57 is a clean, roughly 3/4-inch stone that drains fast and resists rutting. A crushed-stone top course gives a finished look that stays put.
For most builds, crusher run goes down as the base and a cleaner stone tops it. The pairing balances strength and drainage. Match the stone to your soil and how much weight the driveway carries, and you're set.
The most common ordering mistake isn't the stone type, it's buying one layer when the job needs two. A finer top over a coarse base outlasts a single dump of one product almost every time.
Crusher run, #57 stone, and crushed-stone top course are the standard driveway gravels. Crusher run compacts into a strong base, #57 drains well, and a crushed top finishes the surface. Most durable driveways pair a coarse base layer under a finer top course.
Frequently Asked Questions
How much gravel do I need for a 2 car driveway?
A typical 2-car driveway around 24 ft by 20 ft needs about 5.9 cubic yards of gravel at 4 inches deep, which is roughly 8.3 tons. Measure your actual length and width, including the approach from the road, then run them through the formula. Add 5 to 10 percent for compaction and settling.
How deep should a gravel driveway be?
A gravel driveway should be 4 to 6 inches deep total. Four inches handles cars and light traffic; go to 6 inches or more for trucks, RVs, or soft soil. The strongest driveways use a coarse base layer of 3 to 4 inches with a finer top layer of 1 to 2 inches over it.
How do I calculate how many tons of gravel for a driveway?
Multiply length by width by depth in feet, divide by 27 to get cubic yards, then multiply by about 1.4 to get tons. For example, a 20x20 driveway at 4 inches deep is (400 x 0.333) / 27 = 4.9 cubic yards, which equals roughly 6.9 tons of gravel.
How many tons of gravel are in a cubic yard?
One cubic yard of gravel weighs about 1.4 tons, based on construction aggregate density (USGS, 2023). The exact figure shifts a little with stone type and moisture, but 1.4 is a safe planning number. To work the other direction, see our convert tons to cubic yards guide.
Should I order extra gravel for a driveway?
Yes, ordering 5 to 10 percent over your calculated amount is smart. Gravel compacts as it settles, uneven ground absorbs more than the flat-pad math predicts, and a second small delivery often costs more per ton than rounding up the first one. A small cushion saves a return trip.
Get Your Exact Tonnage and a Delivered Price
You've got the formula and the table, so the math part is done. The number that actually matters next is the delivered price for your driveway, and that depends on your address and the stone you pick.
Enter your delivery address on WAYS and you'll get a real instant price on the exact tonnage, no quote forms, no waiting on a callback. Pick your stone, see the total, schedule the drop. We Are Your Supply.