Rock weight chart
These are typical weights for dry, loose rock, the form you buy it in. The calculator uses the “about” column and shows the range so you can see how much a real load might differ.
| Rock | About lb per cu yd | Range, lb per cu yd | About tons per cu yd | Cu yd per ton | Loose lb per cu ft |
|---|---|---|---|---|---|
| Landscape rock (general) | 2,700 | 2,500–2,900 | 1.35 | 0.74 | 100 |
| River rock | 2,700 | 2,500–2,900 | 1.35 | 0.74 | 100 |
| Mexican beach pebbles | 2,800 | 2,600–2,900 | 1.40 | 0.71 | 104 |
| Crushed granite | 2,700 | 2,500–2,900 | 1.35 | 0.74 | 100 |
| Decomposed granite (loose) | 2,600 | 2,400–2,900 | 1.30 | 0.77 | 96 |
| Marble chips | 2,700 | 2,500–2,800 | 1.35 | 0.74 | 100 |
| Limestone chips | 2,700 | 2,500–2,900 | 1.35 | 0.74 | 100 |
| Cobblestone | 2,600 | 2,400–2,800 | 1.30 | 0.77 | 96 |
| Lava rock | 1,200 | 900–1,500 | 0.60 | 1.67 | 44 |
| Riprap (placed) | 3,000 | 2,800–3,400 | 1.50 | 0.67 | 111 |
In metric: 2,700 lb per cubic yard is about 1,600 kg per cubic meter; lava rock at 1,200 lb is about 710 kg per cubic meter.
How to convert yards to tons (and back)
tons = cubic yards × lb per cubic yard ÷ 2,000
cubic yards = tons × 2,000 ÷ lb per cubic yard
- 1 cubic yard of river rock: 1 × 2,700 ÷ 2,000 = 1.35 tons
- 5 tons of landscape rock: 5 × 2,000 ÷ 2,700 = 3.7 cubic yards
- 10 tons of lava rock: 10 × 2,000 ÷ 1,200 = 16.7 cubic yards, more than four times the volume of 5 tons of river rock
- One 0.5 cu ft bag of river rock: 0.5 × 100 lb = about 50 lb
Loose rock versus solid rock
The figures above are for piles. Solid rock (a boulder, a slab, a block) has no gaps, so it is much heavier for its size:
| Stone | Solid, about lb per cu ft | Solid, about lb per cu yd |
|---|---|---|
| Sandstone | 145 | 3,900 |
| Limestone | 160 | 4,320 |
| Quartzite | 165 | 4,460 |
| Granite | 168 | 4,540 |
| Marble | 170 | 4,590 |
| Slate | 172 | 4,640 |
| Basalt | 180 | 4,860 |
Divide a loose weight by the solid weight and you get the share of the pile that is stone. For river rock: 2,700 ÷ 4,540 ≈ 0.6, so a yard of river rock is about 60% granite-like stone and 40% air. For single pieces, use the boulder weight calculator or the granite weight calculator.
What changes the weight of a load
- Moisture. Wet rock weighs more. Porous stone (lava rock, sandstone) can hold a fair amount of water.
- Size mix. A single size of stone has bigger gaps than a mix of sizes. Mixes like “1–3 inch” or rock with fines and dust pack tighter and weigh more per yard.
- Shape. Angular crushed rock and smooth round rock pack differently. Riprap, which is placed and keyed together, ends up denser than a loose pile.
- The stone itself. Basalt is heavier than limestone, and lava rock’s bubbles make it lightest of all.
Why weight matters
- Ordering. Yards sell by the ton or by the cubic yard. Converting lets you compare quotes and know how much area you will cover; the rock coverage calculator does that step.
- Hauling. Check your vehicle’s payload before picking up rock. One cubic yard of river rock is about 2,700 lb, more than many half-ton pickups are rated to carry. Lava rock is the exception.
- Structures. Rock on a roof deck, balcony or raised planter adds a lot of load. Lightweight lava rock is often chosen for that reason, but check the structure’s capacity first.
These weights are typical, not guaranteed. The most reliable number is the one from your supplier for their own product, or the scale ticket from the delivery.
Questions people ask
- How much does a yard of rock weigh?
- Most loose landscape rock weighs about 2,500 to 2,900 pounds per cubic yard, or roughly 1.25 to 1.45 tons. Lava rock is far lighter at about 900 to 1,500 pounds, and riprap is heavier at about 2,800 to 3,400 pounds.
- How much does a cubic foot of rock weigh?
- Loose landscape rock weighs about 90 to 110 pounds per cubic foot. Solid rock, like a boulder, weighs about 145 to 180 pounds per cubic foot depending on the stone.
- How many cubic yards are in a ton of rock?
- About 0.74 cubic yards for most landscape rock at 2,700 pounds per yard, and about 1.67 cubic yards for lava rock at 1,200 pounds per yard.
- Why does a yard of loose rock weigh less than solid rock?
- A pile of rock is roughly 55 to 65 percent stone and 35 to 45 percent air in the gaps between pieces. Solid granite weighs about 4,500 pounds per cubic yard, but as loose chips the same yard weighs about 2,700 pounds.
- Does wet rock weigh more?
- Yes. Water on the surface and in the gaps adds weight, and porous rock such as lava rock and sandstone soaks some up. A load delivered after rain can weigh several percent more than the dry figure.