Gravel Calculator
Enter your dimensions and depth to instantly calculate how much gravel you need — cubic yards for bulk orders or bags for small projects.
Gravel type
Enter your dimensions above to see results
How This Calculator Works
This calculator converts your area and depth into cubic yards (the standard unit for bulk gravel orders) and tons (the unit most suppliers use for pricing).
Rectangle area Area (sq ft) = Length × Width Circle area Area (sq ft) = π × (Diameter ÷ 2)² Volume Volume (cu ft) = Area × Depth (all in feet) Volume (cu yd) = Volume (cu ft) ÷ 27 Weight Weight (lb) = Volume (cu yd) × Density (lb/yd³) × (1 + Waste% ÷ 100) Weight (tons) = Weight (lb) ÷ 2,000
One cubic yard equals 27 cubic feet — this is the conversion that trips up most DIYers. Density values: Pea gravel 2,800 lb/yd³, Crushed stone 2,700 lb/yd³, River rock 2,700 lb/yd³. These are industry-standard figures used by landscape suppliers across the US. Actual weight can vary 5–10% depending on moisture content and specific aggregate source.
The 50-lb bag count is a convenience figure for small projects where buying bags from a hardware store makes sense. For anything over about 2 cubic yards, a bulk delivery from a landscape supply yard is almost always cheaper per cubic yard and avoids the labor of opening and emptying dozens of bags.
Worked Example — 12 × 24 ft Driveway at 4" Deep (Pea Gravel)
Area: 12 × 24 = 288 sq ft
Volume: 288 × (4 ÷ 12) = 96 cu ft ÷ 27 = 3.56 cu yds
With 5% waste: 3.56 × 1.05 = 3.74 cu yds
Weight: 3.74 × 2,800 = 10,472 lb = 5.24 tons
Gravel Density and Weight Reference
Density values used in weight calculations. Actual weight varies ±5–10% by moisture and source.
| Gravel Type | Density (lb/cu yd) | Tons per Cu Yd | Best Use |
|---|---|---|---|
| Pea gravel | 2,800 | 1.40 | Walkways, play areas |
| Crushed stone | 2,700 | 1.35 | Driveways, base layers |
| River rock | 2,700 | 1.35 | Decorative, drainage |
| #57 stone | 2,700 | 1.35 | Drainage, French drains |
| Decomposed granite | 2,600 | 1.30 | Paths, patios |
Coverage per cubic yard at common depths (no waste factor).
| Depth | Sq Ft per Cu Yd | Cu Yds per 100 Sq Ft |
|---|---|---|
| 2" | 162 | 0.62 |
| 3" | 108 | 0.93 |
| 4" | 81 | 1.23 |
| 6" | 54 | 1.85 |
Common Project Sizes
Pea gravel density (2,800 lb/yd³) used for ton estimates. No waste factor included — add 5–10% for your order.
| Area Size | Depth | Cubic Yards | Tons (Pea Gravel) |
|---|---|---|---|
| 10 × 10 ft | 3" | 0.93 | 1.30 |
| 10 × 20 ft | 3" | 1.85 | 2.59 |
| 12 × 20 ft | 4" | 2.96 | 4.15 |
| 12 × 24 ft | 4" | 3.56 | 4.98 |
| 20 × 20 ft | 4" | 4.94 | 6.92 |
| 20 × 40 ft | 6" | 14.81 | 20.74 |
| 30 × 50 ft | 6" | 33.33 | 46.67 |
| Circle 10 ft dia. | 3" | 0.73 | 1.02 |
How to Use This Calculator
Select your area shape at the top — Rectangle for driveways, patios, and pathways with straight sides, or Circle for round garden beds, decorative rings, or circular areas. Enter your dimensions in whatever unit is most convenient; the calculator accepts feet, inches, meters, or centimeters.
Set the Depth to how thick your gravel layer will be. Common depths are 2–3 inches for decorative paths and garden beds, 4 inches for driveways with light vehicle traffic, and 6 inches for heavy-duty driveways or base layers. The default is 3 inches — adjust it to match your project.
Choose a gravel type to get an accurate weight estimate. Pea gravel, crushed stone, and river rock have slightly different densities, which affects how many tons you'll need to order. The cubic yard volume stays the same regardless of type — only the weight changes.
Add a Waste % to account for uneven ground, spillage at edges, and the natural settling that reduces apparent depth. Five percent is typical for a clean, edged rectangular area. Use 10% for irregular ground, curves, or slopes. Results update instantly as you type — there is no calculate button.
Frequently Asked Questions
How deep should driveway gravel be?
A new gravel driveway should have a base layer of 4–6 inches of larger crushed stone (2–3" size) topped with 2–4 inches of smaller gravel like crushed limestone or pea gravel. For a stable surface under vehicle weight, plan on 6 inches total. This calculator uses 3 inches as the default for decorative paths and 6 inches for driveways — adjust the depth field to match your project.
How many cubic yards of gravel do I need?
Multiply your area in square feet by the depth in feet, then divide by 27 to convert to cubic yards. For example, a 12×24 ft driveway at 4 inches deep is: 288 sq ft × 0.333 ft ÷ 27 = 3.56 cubic yards. This calculator does all that conversion automatically — just enter your dimensions and depth.
What is the difference between pea gravel and crushed stone?
Pea gravel is smooth and rounded (3/8" diameter) — comfortable underfoot, great for walkways and play areas, but it shifts and spreads easily without edging. Crushed stone has angular edges that lock together under load, making it far more stable for driveways and high-traffic areas. River rock is similar to pea gravel in shape but larger (1–3"), typically used for decorative drainage beds.
How much does a cubic yard of gravel cover?
One cubic yard of gravel covers approximately 108 sq ft at 3 inches deep, 81 sq ft at 4 inches deep, or 54 sq ft at 6 inches deep. A quick rule of thumb: one cubic yard covers 100 square feet at 3 inches. For driveways, figure one cubic yard per 80–100 sq ft of surface area at the standard 3–4 inch depth.
How many tons of gravel do I need?
Gravel suppliers typically sell by the ton for bulk orders. Pea gravel weighs approximately 1.4 tons per cubic yard (2,800 lbs); crushed stone and river rock weigh about 1.35 tons per cubic yard (2,700 lbs). This calculator converts volume to weight automatically. Share the ton estimate with your supplier when placing a bulk order.
Should I add a waste factor for gravel?
A 5–10% waste factor is appropriate for most gravel projects. Gravel spreads unevenly over rough ground, some spills at edges when filling, and compaction can reduce the apparent depth. For a first-time project or an irregular area with curves and obstacles, use 10%. For a clean rectangular area with established edging, 5% is usually sufficient.
Tips and Warnings
Install edging before ordering. Pea gravel and river rock will migrate outward over time without a physical barrier — plastic landscape edging, steel edging, or timber borders are essential for paths and bed borders. Crushed stone is more self-compacting, but edging still helps it hold a clean line.
Compact in layers for driveways. For a stable driveway base, spread no more than 3–4 inches at a time and compact with a plate compactor before adding the next layer. Dumping 6 inches at once and driving over it is not the same as compacted layers — the base will rut and shift with heavy vehicle traffic.
Use landscape fabric under decorative gravel. A layer of woven landscape fabric (not plastic sheeting — it blocks drainage) before spreading gravel dramatically reduces weed breakthrough and makes the gravel easier to rake clean over the years. Avoid fabric under driveways where you want drainage through the full depth.
Order by the ton, not by the bag. For anything over 1–2 cubic yards, bulk delivery from a landscape supply yard is significantly cheaper per cubic yard than buying 50-lb bags. Get quotes from two local suppliers — gravel prices vary widely by distance from the quarry.
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