Multiply wall length × height × thickness in feet to get cubic feet, divide by 27 for cubic yards, then multiply by about 1.6 for tons of wall stone. A 20 ft long, 3 ft high, 18-inch thick wall needs about 3.3 cubic yards — roughly 5.3 tons.
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Order – tons (includes your waste allowance) so compaction and spillage don’t leave you short.
Stone Wall Calculator Guide
Dry-stack wall estimating is volume arithmetic wearing work gloves: length × height × thickness in feet, divided by 27 for cubic yards, multiplied by about 1.6 tons per yard for dense wallstone. What makes it feel unpredictable is that the thickness is not a free choice — it is set by the height through the mason’s oldest rule: the base must be at least half the wall’s height, and never less than 12 inches. Decide how tall, and the rule decides how thick, which is why the table below can quote stone per linear foot from height alone.
The 15% default waste allowance is not pessimism, it is dry stone. Every wall consumes stones that split during shaping, faces that never find a neighbor, and a steady diet of small fill that vanishes into the core. Builders who order exact volumes finish their walls short, usually with three feet left to go.
How Many Tons of Stone per Foot of Wall?
| Wall height | Base thickness | Tons per linear ft | 20-ft wall |
|---|---|---|---|
| 1 ft | 12 in | ≈ 0.06 | ≈ 1.2 tons |
| 2 ft | 12 in | ≈ 0.12 | ≈ 2.4 tons |
| 3 ft | 18 in | ≈ 0.27 | ≈ 5.3 tons |
| 4 ft | 24 in | ≈ 0.47 | ≈ 9.5 tons |
Notice the curve: doubling height from 2 to 4 feet roughly quadruples the stone, because the wall grows taller and thicker at once. It is the quiet reason 3-foot garden walls are everywhere and 4-footers are rare — and past 4 feet the question stops being tonnage and becomes engineering, which the calculator cannot supply.
Hearting: The Stone You Forgot to Order
A dry wall is not two faces of handsome stone leaning on each other — it is two faces packed solid with hearting, the fist-sized and smaller fill that locks the core. Roughly a third of the wall’s volume disappears into hearting, and running out of it is the classic mid-build crisis, because the tidy pallets from the stone yard skew toward face stone. When ordering, ask specifically for a mix that includes fill, or budget a separate half ton of small stone per 3 tons of wall.
The build follows the old sequence: a trench through topsoil with a compacted stone footing, the biggest stones laid first as the base course, every stone crossing a joint below it, faces battered inward about 1:6, and through-stones spanning the full thickness every few feet of length and height. Cap with your flattest, heaviest material — the capstones are the wall’s roof, shedding water out of the core, and the course visitors will inevitably test by sitting on it.
Size the footing trench fill separately with the crusher run calculator — 6 inches compacted in the trench is cheap insurance under all that tonnage. And if you want rigid joints and a formal face instead of the dry-laid look, the stone masonry calculator prices the mortared version of the same wall, footing and all.
Frequently Asked Questions
How much stone do I need per foot of wall?
A 3-foot-high, 18-inch-thick wall uses about 4.5 cubic feet of stone per linear foot — roughly a quarter ton. Double the height and you double the stone per foot, plus a wider base course.
How thick should a dry-stack stone wall be?
The rule of thumb is a base thickness of at least half the wall height, and never less than 12 inches. A 3-foot garden wall wants an 18-inch base; anything over 4 feet should be engineered.
Should I add extra stone for a dry-stack wall?
Yes — set the waste allowance to at least 15%. Dry stacking is a puzzle: some stones never find a home, others split during shaping, and you always want a surplus of small hearting stones to pack the core.
Does a stone wall need a foundation?
Dry-stack walls under 3 feet sit on a 6-inch compacted crusher-run trench dug below topsoil. Mortared walls need a concrete footing below frost depth, or freeze-thaw movement will crack the joints in the first winters.