Bags vs bulk
Bulk is cheaper for this job
With these prices and $100 delivery, bulk starts to win at about 0.4 cu yd (about 66 sq ft at 2 in), but bags win again at some sizes up to about 0.6 cu yd, and bulk wins at every size above that. Bulk cost rises in half-yard steps.
Delivery for bulk
Typical price (estimate, checked Oct 2026): $50.00–$150.00 per delivery
Use a price like 50.00.
Both costs use your price if you typed one, else the middle of the typical range. Bulk is the order at its price plus one delivery fee. The fee carries over to the gravel, mulch and topsoil calculators. To compare at your own bag and yard prices, switch "Buy it by the" above, enter the price, and switch back.
One cubic yard is 54 bags. Bags make sense for a small patch or when you can't get a truck in; once one delivery fee is spread over a bigger load, bulk by the yard or ton wins.
How it works
The formula
cu yd = cu ft ÷ 27
tons = cu yd × tons per cu yd
bags = cu ft ÷ 0.5, round up
Assumptions
- Weight per cu yd: river rock 1.35, lava rock 0.5, marble chips 1.4 tons. These are typical supplier figures, not exact. Weight changes with rock size, moisture and quarry, so ask your supplier.
- Depth is about twice the rock size: 2 in for rock up to 1 in, 3 in for 1 to 3 in river rock. Thinner and the soil shows through.
- Bulk is ordered in half-yard or half-ton steps, so we round up to the next half.
- A bag holds 0.5 cu ft. Bags are counted by the volume printed on the bag, and the count rounds up.
- Landscape fabric under the rock is listed by area but not priced.
Worked example
A 4 × 20 ft flower bed of river rock, 2 in deep
- 4 × 20 × 2 ÷ 12 = 13.3 cu ft
- In yards: 13.3 ÷ 27 = 0.49 cu yd
- In tons: 0.49 × 1.35 = 0.67 tons
- Bulk order, rounded up to the half yard: 0.5 cu yd
- At $100.00 a yard (the middle of our typical range): 0.5 × $100.00 = $50, plus one $100 delivery = $150
How far does rock go?
| Depth | 1 cu yd covers | 1 ton river rock | 1 ton lava rock |
|---|---|---|---|
| 1 in | 324 sq ft | 240 sq ft | 648 sq ft |
| 2 in | 162 sq ft | 120 sq ft | 324 sq ft |
| 3 in | 108 sq ft | 80 sq ft | 216 sq ft |
| 4 in | 81 sq ft | 60 sq ft | 162 sq ft |
River rock at 1.35 tons and lava rock at 0.5 tons per cu yd. Lava rock is so light that a ton goes much further.
Common bed sizes, river rock
| Size | 2 in | 3 in |
|---|---|---|
| 4 × 20 ft | 0.49 cu yd 0.67 tons | 0.74 cu yd 1.00 tons |
| 5 × 10 ft | 0.31 cu yd 0.42 tons | 0.46 cu yd 0.63 tons |
| 10 × 10 ft | 0.62 cu yd 0.83 tons | 0.93 cu yd 1.25 tons |
| 10 × 20 ft | 1.23 cu yd 1.67 tons | 1.85 cu yd 2.50 tons |
Tons at 1.35 per cu yd. For lava rock, use the cu yd and skip the tons: it weighs about 37% as much.
Questions people ask
How much landscape rock do I need?
Multiply length by width by depth in inches ÷ 12 for cubic feet, then divide by 27 for cubic yards. A 4 × 20 ft bed at 2 in is 0.49 cu yd, about 0.67 tons of river rock or 27 bags.
How much does a ton of river rock cover?
About 120 sq ft at 2 in deep and 80 sq ft at 3 in, at 1.35 tons per cu yd. Ask your supplier for their weight, since it varies.
How deep should landscape rock be?
About twice the size of the rock: 2 in for rock up to 1 in, and 3 in for 1 to 3 in river rock. A 10 × 20 ft bed at 3 in is 1.85 cu yd, about 2.50 tons.
Should I use rock or mulch?
Rock lasts for years, doesn't rot and doesn't blow around, but it costs more up front, holds heat, and is hard to dig through later. Mulch is cheaper, feeds the soil and needs topping up every year or two. Rock is a good fit for dry beds and near the house; mulch for plantings that like cool, rich soil.
How many bags of rock are in a cubic yard?
54 bags. A cubic yard is 27 cu ft, and each bag holds 0.5 cu ft. Some bags are 0.75 or 1 cu ft, so check the label.