How many bags: the formula
Bags = length (ft) × width (ft) × depth (in) ÷ 12 ÷ bag size (cu ft)
Example. A 10 × 4 ft bed at 2 inches: 40 × 0.167 = 6.7 cubic feet. In 0.5 cu ft bags that is 13.3, so 14 bags, or 15 to 16 with a little extra.
Bag coverage chart
| Depth | 0.5 cu ft bag covers | 1 cu ft bag covers |
|---|---|---|
| 1 inch | 6 sq ft | 12 sq ft |
| 2 inches | 3 sq ft | 6 sq ft |
| 3 inches | 2 sq ft | 4 sq ft |
| 4 inches | 1.5 sq ft | 3 sq ft |
Bags per cubic yard
| Bag | Bags per cubic yard (about) |
|---|---|
| 0.5 cu ft | 54 |
| 1 cu ft | 27 |
| 50 lb (general gravel) | 56 |
| 40 lb (general gravel) | 70 |
Bags sold by weight hold different volumes depending on the stone: a 50 lb bag of dense crushed stone holds a little less than a 50 lb bag of lighter river rock. Check the bag for its stated volume if it gives one.
Bags vs bulk
| Bags | Bulk | |
|---|---|---|
| Best for | Small beds, top-ups, aquariums, places a truck can’t reach | Paths, patios, driveways, anything over about a cubic yard |
| Cost per cubic yard | Higher | Lower, plus delivery |
| Handling | Easy to carry in a car | Needs a truck, a place to tip, and a wheelbarrow |
| Leftovers | Return unopened bags at many stores | Leftover pile stays on site |
Rule of thumb: price both. Multiply the bag price by the number of bags, then compare with the bulk price per yard or ton plus the delivery fee. The gravel calculator gives the cubic yards and tons to ask about.
Tips for bagged gravel
- Weight adds up. 20 bags of gravel is about half a ton. Check your car’s or truck’s payload before loading them all.
- Buy a few extra. Unopened bags are easy to return or store for touch-ups.
- Same batch. Colors vary between production runs, so buy all the bags for one area at the same time.
Bag sizes and weights vary by brand. Use the size printed on the bag.
Questions people ask
- How many bags of gravel make a cubic yard?
- 54 bags of 0.5 cubic feet, or 27 bags of 1 cubic foot. In 50 lb bags it is roughly 56 bags of general gravel.
- How much area does a bag of gravel cover?
- A 0.5 cubic foot bag covers about 3 square feet at 2 inches deep, or 2 square feet at 3 inches.
- How much does a 0.5 cubic foot bag of gravel weigh?
- Around 45 to 52 pounds, depending on the stone and how dry it is.
- When is bulk gravel cheaper than bags?
- Usually once you need more than about one cubic yard (54 bags). Compare the bag price × number of bags with the bulk price plus delivery.