How Much Gravel Do I Need?

Quick Answer

To find how much gravel you need, multiply the area in square feet by the depth in inches, then divide by 324 to get cubic yards. If your supplier sells by the ton, multiply the yards by about 1.4. For example, a 12-by-40-foot driveway at 4 inches deep needs about 6 cubic yards, or roughly 8.5 tons. Round up to the next half yard so you have enough after the gravel packs down.

How do you calculate how much gravel you need?

Gravel is sold two ways — by the cubic yard and by the ton — and that trips up more landowners than the math does. Either way, you start by turning your project into cubic yards. There are only three numbers you need: how long the area is, how wide it is, and how deep you want the gravel. Here is the calculation we run when someone calls and asks how much to order.

Step 1: Measure the area in square feet

Multiply length by width in feet. A driveway that is 12 feet wide and 40 feet long is 480 square feet. If the shape is irregular, break it into rectangles, figure each one, and add them up. Gravel is forgiving, so a close measurement is fine.

Step 2: Pick your depth in inches

Two to three inches to top-dress or resurface an existing gravel surface, 4 inches for a walkway or the wearing course of a driveway, and 6 inches or more when you are building a new driveway up from bare ground. Depth swings the order more than anything else, so settle on it before you call in a load.

Step 3: Do the cubic-yard math

Use this formula: square feet × depth in inches ÷ 324 = cubic yards. The 324 comes from the fact that one cubic yard spread 1 inch thick covers exactly 324 square feet. So for a 480-square-foot driveway at 4 inches deep: 480 × 4 = 1,920, then 1,920 ÷ 324 = 5.9 cubic yards. Round up and order 6 yards.

Step 4: Convert to tons if you need to

Plenty of gravel pits and suppliers price by the ton, not the yard. To convert, multiply your cubic yards by about 1.4. So those 6 cubic yards work out to roughly 8.5 tons. It is not an exact figure — dense crushed limestone runs heavier than rounded pea gravel — so if you want it precise, ask the supplier for their yard-to-ton number. That is the same conversion any gravel calculator uses; the coverage chart below does it for you.

Gravel coverage chart: cubic yards and tons by depth

This chart shows how much gravel you need per 100 square feet at common depths, in both cubic yards and tons. Multiply for your own area — a 500-square-foot driveway is five times the row, a 1,000-square-foot pad is ten times it.

One thing the chart cannot show: gravel compacts. A fresh load sits loose, then packs down 15 to 20 percent once it is graded and driven on — more than topsoil does. If you order to the exact number, you can come up short after it settles. Ordering the next half yard up covers it, and the leftover fills in ruts a season later.

How much does a yard of gravel weigh?

A cubic yard of gravel weighs roughly 2,400 to 2,900 pounds — about 1.2 to 1.45 tons. Dense-graded crushed limestone road gravel like 21AA is on the heavy end because it is packed with stone and fines. Rounded pea gravel is lighter. Either way, gravel is heavier than topsoil, and wet gravel weighs more still.

Weight matters for two practical reasons. First, if you are moving gravel by hand, a single yard is 25-plus wheelbarrow loads and will overload a half-ton pickup — most light trucks are only rated for about a yard of gravel at a time. Second, weight is what caps a delivery. Gravel almost always hits the truck's legal weight limit before the dump bed is physically full, which is why it is usually priced and hauled by the ton.

How many yards of gravel fit in a dump truck?

Delivery is priced by the load, so it helps to know what a load actually is. A standard tandem-axle dump truck — the workhorse of most West Michigan gravel deliveries — hauls about 10 to 12 cubic yards of gravel, but because gravel is heavy it usually reaches the legal weight limit — roughly 13 to 15 tons — before the bed fills up. A smaller single-axle truck carries 5 to 7 yards. Larger tri-axle trucks move more where roads and driveways allow it.

Here is the local wrinkle: in early spring, Michigan seasonal weight restrictions — what most people call frost laws — cut how much a loaded truck can legally carry on Oceana County roads while the roadbed thaws. During that stretch, a truck that hauls a full load in July might only be allowed a partial one. That is why spring deliveries can cost more per yard, and why we plan bigger gravel jobs around the calendar. We walk through the same seasonal math for fill and topsoil in our fill dirt cost guide for Michigan.

If your project needs more than a load or two, ordering full loads is almost always cheaper per yard than partial loads, because you are splitting the same trip cost across more material. Our trucking and material delivery service hauls road gravel, crushed stone, sand, fill dirt, and screened topsoil across Oceana County and the surrounding counties, and we will tell you straight whether one big load or two smaller ones makes more sense for your access.

How much gravel do I need for a driveway?

Driveways are the most common gravel question we get, and the answer depends on whether you are refreshing one or building it from scratch. A worn driveway usually needs 2 to 3 inches of fresh gravel to bring it back. A brand-new driveway wants 4 to 6 inches total, and often more on the soft, sandy ground common around here.

A driveway that lasts is built in layers. You start with a coarse base course of larger crushed stone or crushed concrete to spread the load and drain water, then cap it with a dense-graded road gravel that packs into a hard driving surface. Skipping the base is the most common reason a new driveway sinks or turns to washboard within a year — the top gravel just works down into the sand.

Worked example

Say your driveway is 12 feet wide and 50 feet long — 600 square feet. For a 4-inch top course, the chart says about 1.2 yards per 100 square feet, so 6 × 1.2 = 7.2 cubic yards, or roughly 10 tons. Add a base course underneath and you can double that. It adds up fast, which is exactly why measuring first beats guessing.

If you want the installed cost rather than just the material, we break down driveway pricing in our gravel driveway cost guide for Michigan. And if the ground needs shaping first — a crown for drainage, a culvert at the road, or a soft spot dug out — our land services crew can grade the base and lay the gravel in one visit.

What kind of gravel should you order?

"Gravel" covers a lot of different materials, and ordering the wrong one is an expensive mistake. Here are the ones that come up most on West Michigan jobs:

• 21AA road gravel (crushed limestone). The standard driveway top course in Michigan — a dense-graded mix of crushed stone and fines that packs into a hard, drivable surface. This is what most folks mean by "driveway gravel" around Oceana County.
• Crushed concrete or larger base stone. A coarser, cheaper base course that goes under the road gravel to spread the load and drain water on soft ground.
• 6A or clean crushed stone. Larger, washed stone with no fines — great for drainage, French drains, and mud control, but it stays loose and does not pack.
• Pea gravel. Small, rounded, decorative stone for paths and patios. It looks good but shifts underfoot and under tires, so it is a poor choice for a driving surface.

When in doubt, tell us the job — driveway, drainage, or décor — and we will steer you to the right material rather than the priciest one.

Buying gravel in Oceana County and West Michigan

Once you know your yardage, the next question is what to order and when. A few things worth knowing before you buy gravel around New Era, Hart, Shelby, and the rest of Oceana County:

• Know whether you are buying by the yard or the ton. Pits often quote by the ton, landscape yards by the yard. Get both on the same basis before you compare prices, and use 1.4 tons per yard to translate.
• Our ground runs sandy. A lot of West Michigan soil is sand-based, which drains well but gives gravel nothing firm to sit on. That is why a good base course matters more here than it does on clay.
• Order ahead in the busy season. Late spring through summer is peak project season and haulers book up. A few days' notice usually gets you a delivery window that fits your schedule.
• Mind the frost laws in spring. Early-season weight restrictions mean smaller legal loads on county roads, so deliveries can cost a bit more per yard until the ground firms up.

The fastest way to get an accurate number is to give Aaron a call at (231) 638-8967 with your rough dimensions, or use the contact form. We will figure the cubic yards, convert to tons, quote the gravel delivered, and haul it to your site.

Frequently asked questions