How to Use This Gravel Calculator
Working out how much gravel to order takes four quick steps. First, measure the length and width of the area you want to cover — a tape measure and a helper make this a five-minute job. Second, choose your depth: 2–3 inches is standard for walkways, patios, and landscaping beds, while driveways need 4–6 inches installed in compacted layers. Third, select your gravel type so the calculator applies the correct density — pea gravel, crushed stone, and road base all weigh differently per cubic yard. Finally, click Calculate and you'll get your answer in cubic yards (how suppliers sell bulk gravel), tons (how it's weighed and delivered), and bags (if you're buying from a home improvement store).
If your area is irregular, split it into rectangles, calculate each one, and add the results together. For circular areas, multiply the radius by itself, then by 3.14, to get the square footage — then use that as your length with a width of 1.
The Gravel Formula (With a Worked Example)
The math behind the calculator is straightforward. Gravel is sold by volume (cubic yards) or by weight (tons), and both come from the same three measurements:
Tons = Cubic yards × material density (tons per cubic yard)
Worked example: Suppose you're covering a 20 ft × 10 ft patio area with 3 inches of crushed stone. First convert the depth to feet: 3 ÷ 12 = 0.25 ft. The volume is 20 × 10 × 0.25 = 50 cubic feet. Divide by 27 to get 1.85 cubic yards. Crushed stone weighs about 1.5 tons per cubic yard, so you need 1.85 × 1.5 = 2.78 tons. Adding a 10% buffer for compaction, you'd order 3 tons — at $35 per ton, that's roughly $105 plus delivery.
Gravel Weight by Type
Density is what turns volume into weight, and it varies meaningfully between materials. Smooth, rounded stones like pea gravel and river rock pack less tightly than angular crushed stone, and mixes containing fines (like crusher run) are heavier still. The table below shows the densities this calculator uses.
| Gravel Type | Tons per Cubic Yard | Lbs per Cubic Foot | Typical Uses |
|---|---|---|---|
| Pea Gravel | 1.40 | ~104 | Walkways, playgrounds, landscaping |
| Crushed Stone (3/4") | 1.50 | ~111 | Driveways, drainage, base layers |
| Crusher Run / Road Base | 1.60 | ~119 | Driveway base, compacted pads |
| River Rock | 1.35 | ~100 | Decorative beds, dry creek beds |
| Decomposed Granite | 1.60 | ~119 | Paths, patios, xeriscaping |
| Sand & Gravel Mix | 1.55 | ~115 | Concrete mixing, base fill |
For a full set of coverage tables at every common depth, see our gravel coverage chart.
How Deep Should Your Gravel Be?
Depth is the number people most often get wrong — and it has the biggest impact on how much you order. Too shallow and the gravel migrates, ruts, and lets weeds through; too deep and you've wasted money and made walking difficult. Use these proven depth standards for common projects:
| Project | Recommended Depth | Notes |
|---|---|---|
| Walkways & paths | 2–3 inches | Over landscape fabric to block weeds |
| Landscape/mulch beds | 2–3 inches | Decorative stone over fabric |
| Driveways (new) | 4–6 inches total | Two to three compacted 2–3" lifts; see our driveway calculator |
| Driveway top-up | 1–2 inches | Fresh surface layer over existing base |
| Patio base | 4 inches | Compacted crusher run under pavers |
| French drains | 12 inches | Surrounding the drain pipe |
Who This Calculator Is For
Homeowners planning a gravel driveway, walkway, or patio use this tool to get an order quantity before calling suppliers — bulk gravel is quoted per ton or per yard, so showing up with the right number avoids over-ordering (wasted money) or under-ordering (a second delivery fee). Landscapers and contractors use it for fast on-site estimates when quoting jobs. DIYers buying bagged gravel use the bag count to know exactly how many 0.5 cubic foot bags to load at the store — and to see the point where bulk delivery becomes cheaper, which is usually around 1 cubic yard (54 bags).