Gravel Calculator: How Much Gravel Do You Need?

I Spent 200 Bucks on Gravel I Didn't Need

True story. I was putting in a gravel pad for a shed — nothing fancy, maybe 10 by 12 feet — and I eyeballed the amount I'd need. Drove to the landscape supply yard, told the guy "give me about 5 tons," and he didn't even blink. Loaded me up. I got home, dumped it all, spread it out, and had this massive pile left over that sat in my driveway for three months. My wife was thrilled (she was not thrilled).

The thing is, gravel math isn't hard. It's just that nobody does it before they order, and then you're either making a second trip or explaining to your spouse why there's a gravel mountain blocking the garage.

So yeah, let's figure this out properly.

The Actual Math Behind Gravel Quantities

Gravel is sold by the ton or by the cubic yard, depending on where you are and who you're buying from. Either way, you need to know your volume first, and then convert that into a weight your supplier understands. Here's the formula that'll save you from my driveway situation:

Let me walk through a real example because formulas by themselves are kind of useless until you see them in action.

Say you're building a gravel driveway that's 30 feet long, 10 feet wide, and you want 4 inches of gravel depth. Here's what happens:

• Step 1: Convert 4 inches to feet → 4 ÷ 12 = 0.333 feet
• Step 2: Volume = 30 × 10 × 0.333 = about 100 cubic feet
• Step 3: Cubic yards = 100 ÷ 27 = roughly 3.7 cubic yards
• Step 4: Tons = 3.7 × 1.4 = about 5.2 tons

So you'd order around 5.5 tons to be safe. Not 8 tons. Not "a few loads." Five and a half tons, give or take.

That conversion factor of 1.4 is where people get tripped up, honestly. Different gravels weigh different amounts. Pea gravel is lighter than crushed limestone, which is lighter than river rock. Here's a quick reference:

These numbers shift depending on moisture content and how tightly the gravel is packed, but they'll get you in the ballpark of what you actually need. And being in the ballpark is way better than guessing.

How Deep Should Your Gravel Be?

This depends entirely on what you're doing with it.

I've seen homeowners put down 1 inch of gravel on a walkway and wonder why they can see dirt after two rainstorms. And I've seen contractors spec 12 inches of base for a residential driveway that'll never see anything heavier than a minivan. Both are wrong, just in opposite directions.

Here's what I've found works after years of doing this stuff:

• Decorative ground cover or garden paths: 2 to 3 inches is plenty
• Walkways with foot traffic: 3 to 4 inches
• Driveways (light vehicles): 4 to 6 inches — and honestly, I'd lean toward 6
• Driveways (heavy trucks, equipment): 8 to 12 inches, usually in two or three lifts with compaction between each
• Shed pads or small structure bases: 4 to 6 inches of compactable gravel like crusher run

If you're doing a

Ordering Tips (From Someone Who's Messed This Up)

Always add 10% to your calculated amount. Always.

Gravel settles, spills off the edges, gets pushed around during spreading, and some of it inevitably ends up in your lawn or wherever you don't want it. That 10% buffer has saved me on basically every project since I started actually doing the math. On my

A few more things I wish someone had told me earlier: if you're ordering by the truckload, a standard dump truck carries about 10 to 14 tons depending on the truck. A tandem axle can haul closer to 20. So if your calculation says you need 7 tons, that's one truck — don't let anyone talk you into two loads. Also, delivery fees can be anywhere from 50 to 150 depending on distance, and some yards have a minimum order of like 2 or 3 tons. Worth calling ahead.

If you're working on a bigger project and need to figure out

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One more thing — and this is the kind of detail that separates a project that lasts from one that doesn't — if you're putting gravel over bare soil, put down landscape fabric first. It won't stop every weed, but it'll stop most of them, and it keeps the gravel from slowly sinking into the dirt over the years. I skipped this step on a patio area back in 2018 and I'm still dealing with the consequences.

For anyone doing a full