How Much River Rock for 100 Square Feet?
How much river rock for 100 square feet depends on depth. At 3 inches you need about 0.93 cubic yards, roughly 1.2 tons at 1.35 tons per yard. Going to 4 inches raises it to 1.7 tons.
Volume and tonnage calculator →River rock for 100 sq ft by depth
| Depth | Cubic yards | Tons | Tons +10% |
|---|---|---|---|
| 2 in | 0.62 | 0.8 | 0.9 |
| 3 in | 0.93 | 1.2 | 1.4 |
| 4 in | 1.23 | 1.7 | 1.8 |
Working it out
- 100 sq ft × (3 ÷ 12) ft = 25.0 cubic feet.
- ÷ 27 = 0.93 cubic yards.
- × 1.35 tons per yard = 1.2 tons.
About river rock
River rock is mostly decorative and for drainage beds. It is not meant to be driven on and tends to roll if used as a walking surface. Typical weight: 1.25 to 1.45 tons per cubic yard.
Getting the order right
- Measure odd shapes in pieces. Split curves and L-shapes into rectangles and add them.
- Add a margin. About 10 percent covers compaction and low spots.
- Bulk or bags. This is small enough that bags may compete with a bulk minimum; price both.
- Prep first. Remove sod, compact the subgrade and set edging before the stone arrives.
Use the volume and tonnage calculator for any other size.
Where river rock fits
Good uses:
- Dry creek beds and drainage swales
- Decorative borders and planting beds
- Around downspouts to stop splash erosion
Think twice for:
- Walking surfaces
- Driveways
- Bases under slabs or pavers
Quick reference numbers
- Per inch over 100 sq ft: about 0.42 tons of river rock (0.31 cubic yards).
- Per inch over 1,000 sq ft: about 4.2 tons.
- Another size for comparison: a 15x30 area at 3 inches takes about 5.6 tons.
- Weight used here: about 1.35 tons per cubic yard.
Common estimating mistakes
- Skipping drainage. Water sitting under any surface softens the base and leads to ruts and potholes.
- Mixing up cubic yards and tons. Yards are volume, tons are weight; convert with the product’s weight per yard.
- Assuming every supplier uses the same weight. Two yards selling the same product name can quote different tons per yard.
- Measuring only the main rectangle. Aprons, turnouts and curved edges add real square footage.
Questions people ask
How many tons of river rock for 100 square feet?
About 1.2 tons at 3 inches deep.
How many cubic yards of river rock for 100 square feet?
About 0.93 yards at 3 inches.
How much river rock for 100 square feet at 2 inches?
About 0.8 tons, or 0.62 cubic yards.
How much does a yard of river rock weigh?
About 1.25 to 1.45 tons.
Should I add extra?
Yes, about 10 percent is a common allowance.
Related guides
- How Much Does a Ton of River Rock Cover?
- Tons to Cubic Yards for Gravel: Conversion Chart
- How Much Does a Ton of Gravel Cover? Depth Chart
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