To work out how much gravel you need, multiply the area's length, width, and depth in feet to get cubic feet, then divide by 27 to get cubic yards. For weight, multiply the cubic feet by 105 pounds and divide by 2,000 to get US tons. As a quick rule, a 4-inch-deep layer needs about 0.012 cubic yards (roughly 0.018 tons) of gravel per square foot. Always add 10–15% extra for compaction and spreading loss.
How do you calculate how much gravel you need?
Gravel is priced and delivered by volume (cubic yards) or weight (tons), so every estimate starts with the volume of the space you are filling. The math is the same one the gravel calculator runs for you:
- Measure length and width in feet. For an irregular shape, split it into rectangles, size each one separately, and add the results.
- Pick a depth and convert it to feet. Most gravel layers are measured in inches, so divide by 12, and a 4-inch layer is 0.333 ft.
- Multiply length × width × depth to get the volume in cubic feet.
- Divide cubic feet by 27 to get cubic yards (there are 27 cubic feet in a cubic yard).
- Convert to tons if your supplier sells by weight: multiply cubic feet by 105 (the approximate weight of gravel per cubic foot) and divide by 2,000.
That single density figure, about 105 pounds per cubic foot or roughly 1.4 tons per cubic yard, is what turns a volume into an order weight. It holds for most dry construction gravel and crushed stone, though wet or compacted material weighs more.
How much gravel do I need per square foot?
If you already know your total square footage, you can skip straight to a per-square-foot figure and multiply. The table below shows how much gravel one square foot needs at common depths, plus how far a single ton stretches.
| Depth | Cubic yards / ft² | Tons / ft² | Coverage per ton |
|---|---|---|---|
| 2 inches | 0.006 | 0.009 | ~100 ft² |
| 3 inches | 0.009 | 0.014 | ~65 ft² |
| 4 inches | 0.012 | 0.018 | ~50 ft² |
| 6 inches | 0.019 | 0.027 | ~33 ft² |
So a 500-square-foot patio at 2 inches deep needs about 3 cubic yards or 4.5 tons, while the same patio at 4 inches deep needs roughly double that. Coverage shrinks as depth grows because you are stacking more material into the same footprint.
How deep should gravel be?
Depth is the variable that most changes your order, so it is worth getting right before you measure anything else:
- Decorative top layer: 2 inches over an existing base or landscape fabric.
- Walkways and garden paths: 2–3 inches for a firm, comfortable surface.
- Driveways: at least 4 inches of gravel, usually built up in two layers (a coarse base course and a finer top course) over compacted ground.
- Heavy-use or soft ground: 6 inches or more, often with a larger crushed-stone base underneath.
For loose, rounded stone like pea gravel, keep walkable layers on the shallower side so the surface stays firm underfoot.
How much gravel do I need for a driveway?
Driveways are the most common gravel project, so here is a full worked example. Say your driveway is 20 feet long, 10 feet wide, and you want a 4-inch layer:
- Depth in feet: 4 ÷ 12 = 0.333 ft
- Volume: 20 × 10 × 0.333 = 66.7 cubic feet
- Cubic yards: 66.7 ÷ 27 = 2.47 cubic yards
- Tons: 66.7 × 105 ÷ 2,000 = 3.5 tons
- Add 10–15% for compaction: order about 2.8 cubic yards or 4 tons
Because gravel settles, the extra 10–15% is not optional for a driveway: the surface will lose noticeable height after the first few weeks of traffic. If you are pouring a base for concrete or pavers instead, work the depth out in cubic yards the same way and order to the compacted depth you need.
What type and size of gravel should you use?
Gravel is sold in grades by stone size, and the right one depends on the layer:
- Base course: larger crushed stone, often 1 to 2 inches (sometimes sold as #2 or crusher run), forms a stable, load-bearing bottom layer.
- Top course: smaller angular stone around 3/8 to 3/4 inch packs tightly and locks in place, which is why crusher run and #57 stone are popular for driveways.
- Decorative and walkable areas: rounded pea gravel at about 3/8 inch is comfortable underfoot but shifts more, so it suits paths and patios rather than driveways.
Angular crushed stone interlocks and stays put, while rounded gravel drains well but migrates, so most driveways use a crushed-stone base with a crushed-stone top instead of rounded stone. Match the stone size to the job before you order, because switching grades later means paying for a second delivery.
How do you lay and compact gravel?
Ordering the right volume is only half the job; how you place it decides how long it lasts:
- Clear and grade the area, removing sod and topsoil down to firm subsoil.
- Lay landscape fabric to stop the gravel sinking into the ground and to block weeds.
- Spread the base course in a layer about 4 inches thick and rake it level.
- Compact each layer with a plate compactor or roller before adding the next, because loose gravel keeps settling.
- Add the top course and compact again, crowning the centre slightly so water runs off.
This is exactly why the calculator adds a 10 to 15 percent margin: compaction physically reduces the volume, so the gravel you spread is always more than the finished depth suggests. Skipping compaction is the most common reason a gravel driveway develops ruts and potholes within a single season.
How much does gravel cost?
Bulk gravel typically runs about $15 to $75 per cubic yard, or roughly $10 to $50 per ton delivered, depending on the stone type and your distance from the quarry. Decorative and specialty stone costs more than plain crushed stone. Because delivery is a large share of the bill, ordering your full quantity in one drop is cheaper than topping up later, which is another reason to measure carefully and add the compaction margin before you order.
How is gravel sold, by the yard or the ton?
Suppliers quote gravel either by the cubic yard or by the ton, and the two are easy to convert: one cubic yard of typical gravel weighs about 1.4 tons. Bulk delivery is far cheaper per unit than bagged gravel, so for anything larger than a small garden bed, ordering by the cubic yard or ton almost always wins on price.
Gravel and crushed stone are not a niche material, either: construction sand and gravel together make up one of the largest segments of U.S. industrial mineral production, according to the U.S. Geological Survey, and the average American relies on several tons of aggregate every year per figures from the National Stone, Sand & Gravel Association. When you call in an order, give the supplier both numbers, your cubic yards and your tons, so they can load the right amount regardless of how they price it.
Once you have your measurements, run them through the gravel calculator to get cubic yards, tons, and cubic feet instantly, then add your compaction margin before you order.