How to Use This Gravel Calculator
Ordering the right amount of gravel saves money and avoids leftover piles or return delivery fees. Gravel is sold by the cubic yard or ton—this calculator converts your project dimensions into both units so you can order accurately from any supplier.
- Choose your area shape. Most driveways and patios are rectangles. Use the circle option for fire pits, tree rings, and round patios. The triangle option handles wedge-shaped areas.
- Enter dimensions in feet. Measure the full area you want to cover. For irregular shapes, break them into smaller rectangles and calculate each separately.
- Set your desired depth. Driveways need 4-6 inches of base gravel. Walkways and landscaping typically need 2-3 inches. Drainage projects may need 6-12 inches.
- Select gravel type. Different gravels have different weights per cubic foot, which affects how many tons you need for the same volume.
Gravel Volume Formula
The formula for gravel volume is straightforward:
Volume (cu ft) = Area (sq ft) × Depth (ft)
Cubic Yards = Volume (cu ft) ÷ 27
Tons = Volume (cu ft) × Weight per cu ft ÷ 2,000
One cubic yard equals 27 cubic feet. Gravel suppliers typically sell by the cubic yard for bulk orders or by the ton for larger quantities. Knowing both values helps you compare pricing across suppliers.
Sample Gravel Calculations
| Area | Depth | Cubic Yards | Tons (crushed stone) |
|---|---|---|---|
| 10 × 10 ft | 2 in | 0.62 | 0.83 |
| 10 × 20 ft | 3 in | 1.85 | 2.50 |
| 20 × 20 ft | 4 in | 4.94 | 6.67 |
| 12 ft circle | 2 in | 0.70 | 0.94 |
| 50 × 3 ft path | 3 in | 1.39 | 1.88 |
Common Mistakes When Ordering Gravel
- Not accounting for compaction. Gravel compacts 20-30% when tamped. If you need 4 inches after compaction, spread 5-6 inches of loose gravel.
- Forgetting edge containment. Without borders, gravel migrates into lawn and garden beds. Install edging, landscape timbers, or pavers before adding gravel.
- Skipping the fabric layer. Landscape fabric prevents gravel from mixing with soil. Without it, you'll need to replenish gravel every 1-2 years.
- Ordering by volume when the supplier sells by weight (or vice versa). Confirm the unit of sale before ordering. One cubic yard ≠ one ton—crushed stone is about 1.35 tons per cubic yard.
- Not preparing the base. Remove vegetation, grade the area for drainage (1-2% slope), compact the soil, then lay fabric before adding gravel.
Worked Example: 12×50 ft Gravel Driveway
A standard single-car gravel driveway calculation:
- Dimensions: 12 × 50 feet = 600 sq ft
- Depth: 4 inches (0.333 ft)
- Gravel type: Crushed stone (100 lbs/cu ft)
Step 1: Volume = 600 × 0.333 = 200 cubic feet
Step 2: Cubic yards = 200 ÷ 27 = 7.41 cubic yards
Step 3: Weight = 200 × 100 = 20,000 lbs = 10 tons
At $25-45 per ton delivered, budget $250-450 for gravel plus $50-150 for delivery. Add 15% extra for compaction and uneven ground: order ~11.5 tons.
Frequently Asked Questions
How much gravel do I need for a driveway?
A typical residential driveway (12 × 50 feet) with a 4-inch base layer needs approximately 7.5 cubic yards or 10 tons of crushed stone. Add 2 inches of surface gravel (pea gravel or decorative stone) for another 3.7 cubic yards. Total cost ranges from $300-1,500 depending on stone type and your region.
How deep should gravel be?
For driveways, use 4-6 inches of base gravel plus 2 inches of surface gravel. Walkways need 2-3 inches. Landscape beds require 2-4 inches. French drains need 6-12 inches. Paver bases typically require 4-6 inches of compacted gravel. Deeper is always more stable, but costs increase proportionally.
How many tons is a cubic yard of gravel?
One cubic yard of gravel weighs approximately 1.35 tons (2,700 lbs) on average. This varies by type: pea gravel weighs about 1.29 tons/yd³, crushed stone 1.35 tons/yd³, and river rock 1.35 tons/yd³. Wet gravel weighs 15-20% more than dry gravel. Most suppliers sell by the ton.
What type of gravel should I use?
Crushed stone (#57 or #411) is best for driveways and bases because angular edges lock together. Pea gravel works well for walkways, patios, and drainage. River rock is decorative but shifts underfoot. Decomposed granite compacts well for paths. Limestone is affordable and widely available. Use geotextile fabric underneath to prevent gravel from sinking into soil.
How much extra gravel should I order?
Order 10-15% extra to account for compaction, uneven ground, and spreading beyond edges. Gravel compacts by about 30% when machine-compacted. If your ground is uneven, order 20% extra. It's much cheaper to order extra upfront than to arrange a second delivery, which typically costs $50-150.
Can I put gravel directly on dirt?
You can, but it's not recommended. Without a barrier, gravel sinks into soil over time, requiring constant replenishment. Lay landscape fabric or geotextile fabric first to separate gravel from soil. For driveways, compact the soil first, add fabric, then add gravel in layers—compacting each layer for stability.