Multiply basket length × width × height in feet, divide by 27 for cubic yards, then multiply by 1.6 for tons of gabion stone. A standard 6 × 3 × 3 ft basket holds 2 cubic yards — about 3.2 tons. Add only 5% waste, since the cage fixes the fill volume.
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Order – tons (includes your waste allowance) so compaction and spillage don’t leave you short.
Gabion Stone Calculator Guide
Gabions invert the usual estimating problem: instead of spreading stone across an open area, you are filling a container with hard edges. That makes the math unusually honest — basket length × width × height is the volume, full stop — and it is why this calculator uses basket dimensions and a slim 5% waste factor rather than the 10–15% typical of loose spreading. The cage cannot hold more than it holds.
The default density of 1.6 tons per cubic yard reflects rock as it packs inside a basket: large angular stones with meaningful voids between them. If a supplier quotes gabion stone by the ton, this is the figure that turns your basket count into a truck order.
How Many Tons Does Each Gabion Basket Hold?
Standard basket formats and their fill, at 1.6 tons per cubic yard:
| Basket (ft) | Volume | Gabion stone |
|---|---|---|
| 3 × 3 × 3 | 1.0 yd³ | 1.6 tons |
| 6 × 3 × 3 | 2.0 yd³ | 3.2 tons |
| 9 × 3 × 3 | 3.0 yd³ | 4.8 tons |
| 12 × 3 × 3 | 4.0 yd³ | 6.4 tons |
| 6 × 3 × 1.5 (mattress) | 1.0 yd³ | 1.6 tons |
A wall is just baskets in a row: a 30-foot run of 3-foot-tall baskets, one course high, is five 6-footers — 16 tons of stone. Add a second course and the order doubles, so gabion projects reach full-truck quantities faster than almost any landscape feature of similar size.
Filling Baskets So They Stay Square
- Set baskets on compacted ground or a leveled stone pad — a leaning cage only leans further once loaded.
- Fill in 12-inch layers, installing the internal bracing wires between layers so the faces cannot belly outward.
- Hand-place the visible faces with the flattest stones, tightest joints outward; dump-fill only the hidden core.
- Pack corners deliberately — voids at corners are what make a finished wall look under-filled.
- Overfill by an inch before closing the lid, since the fill settles slightly and a taut lid keeps the top course flat.
Gabions often share a site with loose rock armor — the riprap calculator covers the un-caged version of the same erosion-control job, and the river rock calculator is the place to size rounded stone if your baskets are decorative rather than structural.
Frequently Asked Questions
What size stone goes in a gabion basket?
Angular rock 4–8 inches across for standard baskets — every stone must be larger than the mesh opening, which is typically around 3 inches. Angular stone locks together and keeps the basket faces flat; undersized rock simply falls through.
How many tons fill a gabion basket?
At 1.6 tons per cubic yard placed, a 3 × 3 × 3 ft basket takes about 1.6 tons and a 6 × 3 × 3 ft basket about 3.2 tons. Multiply out your wall run and the tonnage climbs fast — ten 6-foot baskets is a 32-ton order.
Can I fill gabions with river rock?
Yes, if the stones exceed the mesh size — rounded rock gives a softer, water-worn look that suits garden walls. Expect slightly more bulging than with angular stone and brace long faces during filling, since rounded rock does not interlock.
Do I hand-place gabion stone or dump it in?
Both. Hand-lay the visible faces like dry stone masonry so the wall shows tight, flat coursing, then machine- or bucket-fill the hidden core. Hand-placed faces also stop the mesh from deforming under the fill pressure.