Gravel Calculator
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Enter a driveway, path or trench's length, width and depth, and this calculator returns cubic feet, cubic yards and an estimated weight using a 95 lb/ft³ density, the same figure used across this site's weight reference. Weight matters here more than with most materials, since suppliers usually deliver gravel by the ton.
Base Layer vs. Top Layer
A gravel driveway is really two different layers with two different jobs. The base layer, larger, angular stone compacted several inches deep, provides load-bearing structure and drainage beneath the surface. The top layer, smaller, more rounded stone 3–4 inches deep, is what you actually drive and walk on. Calculating each layer separately with its own depth, rather than guessing one blended figure for the whole driveway, keeps the material order accurate for both jobs.
Drainage applications flip the priority: a French drain or drainage trench doesn't need a hard-wearing surface course at all, just enough depth, usually 6 inches or more, that water has room to move through the gaps between stones without backing up. Excavating the trench to the right depth before laying gravel is its own calculation, covered on the fill dirt and excavation page.
Common Gravel Grades
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Crusher run / #411
Crushed stone with fines mixed in, compacts tightly, the standard choice for a driveway base layer.
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#57 stone
Clean, angular stone about ¾–1 in across with no fines, drains well, the usual pick for French drains and drainage trenches.
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Pea gravel
Small, rounded stone about ⅜ in across, comfortable underfoot, common for walkways and decorative surface layers rather than structural base.
The density figure this calculator uses, 95 lb/ft³, is a reasonable average across these grades, but crusher run with more fines packed in can run somewhat heavier, while clean, uniformly-sized stone with more air gaps between pieces runs somewhat lighter. If you know your supplier's specific density, the weight conversion tool's custom-density option gives a more precise weight than this page's built-in average.
Volume Isn't the Whole Order, Weight Is
Most aggregate suppliers price and deliver gravel by the ton, not by the cubic yard, which means the weight output on this calculator often matters more than the volume figures above it. At roughly 95 lb per cubic foot, gravel is dense enough that even a modest driveway order adds up to several tons quickly, a 20 ft × 10 ft drive at 4 inches deep comes to about 133 ft³, which is already 6.3 tons of stone. For the full reasoning behind why volume alone doesn't determine weight, moisture, compaction and particle size all move the number, see the material weight calculator.
Gravel delivered as a loose stockpile rather than spread flat also happens to settle into a natural cone shape, which is the same geometry covered on the volume formula reference page's cone calculator, useful if you're trying to estimate how much is left in a dumped pile rather than calculating a fresh order.
Worked Example: A Drainage Trench
A trench 20 ft long, 1.5 ft wide, 6 in deep
- Convert depth: 6 in ÷ 12 = 0.5 ft
- Volume: 20 × 1.5 × 0.5 = 15 ft³
- Weight: 15 × 95 = 1,425 lb
This trench needs about 15 cubic feet of gravel, weighing roughly 1,425 lb.
At under a ton, this is a job most people can haul in a pickup rather than arranging a dedicated delivery, check your vehicle's payload rating against the weight figure before loading it all at once.
Compaction and Edging
A driveway base layer needs mechanical compaction, a plate compactor passed over the stone in lifts of a few inches at a time, to actually reach the load-bearing density the material is capable of. Gravel dumped and left loose settles unevenly under vehicle traffic instead of compacting uniformly, which is how driveways develop ruts and low spots within a season or two even when the initial material order was correctly sized. Compacting in lifts rather than all at once also means the depth you're ordering material for should already assume the finished, compacted depth, order for the target depth, not for a looser pre- compaction thickness that will settle down to it anyway.
Edging, a physical barrier along the driveway or path's sides, whether plastic landscape edging, brick, or poured concrete, matters more for gravel than for almost any other material on this site, since loose stone migrates sideways under traffic and weather without something to contain it. A driveway without edging typically needs periodic top-up material just to replace what's migrated off the sides, which is worth budgeting for separately from this calculator's one-time initial order figure.
Bulk Delivery and Access
Like topsoil, gravel arrives as a dumped pile that still needs moving into place, a supplier's truck tips the load at the nearest accessible point, not necessarily exactly where the finished surface needs to be. For anything beyond a few tons, confirm the delivery vehicle can actually reach the site: a standard dump truck needs a clear, firm path at least 8–10 ft wide, and steep driveways or soft ground can turn a straightforward delivery into a logistical problem after the truck is already committed to the load. Spreading and compacting several tons by hand with a rake and a hand tamper is realistic for a small path but becomes a multi-day job at driveway scale, where renting a plate compactor for an afternoon is usually worth the cost.
If a job needs more than one delivery, a base layer today, a top layer once it's settled, calculate and order each layer's volume separately using this calculator rather than estimating a single combined figure, since the two layers use different grades of stone at different depths and rarely arrive from the same part of a supplier's yard.
Permeable and Erosion Considerations
Gravel's open, air-filled structure, the same property that makes it lighter than solid stone by volume, also makes it naturally permeable, which is why it's the default choice for drainage applications covered earlier on this page. That same permeability works against it on a slope, where water flowing through and under a loose gravel bed can wash fines out from underneath and destabilize the surface layer over time. A geotextile fabric laid beneath the base layer, separating the gravel from the native soil below, is the standard fix and doesn't change any of this calculator's volume math, just the long-term stability of the finished job.
Frequently Asked Questions
How deep should a gravel driveway surface layer be?
About 3–4 inches for the top surface course over a compacted base, deeper than that mostly adds cost without adding durability, since the base layer underneath is what actually carries vehicle weight. A drainage bed, by contrast, is often filled 12 inches deep or more, since its job is water capacity rather than a driveable surface.
Why does a drainage trench need more gravel depth than a driveway?
A drainage run or French drain needs a deeper bed, typically 6 inches or more, because its job is to keep water moving through the gravel's air gaps, not to bear weight, so more depth means more capacity to move water before it backs up.
Does gravel weight change much between wet and dry?
Yes, wet gravel can weigh noticeably more than dry gravel of the same volume, because water fills the air gaps between stones. If you're near a vehicle payload or trailer weight limit, check the weight figure on this page rather than assuming the dry density always applies.
Should I order gravel by weight or by volume?
Suppliers usually quote and deliver by weight (tons) for bulk aggregate even though you plan the job by volume, this calculator's weight output converts your cubic-feet figure into the pounds a supplier's ton-based quote will actually reference. Keep both figures on hand when calling a supplier, since delivery minimums are usually set against the weight number.