The Stone Wall Calculator estimates how many tons of stone you need for a natural stone wall, whether dry-stacked or mortared.
It finds the wall volume (length × height × thickness), removes the gaps between irregular stones (voids), and multiplies by the stone’s density: Weight = volume × (1 − voids) × density. Stone is usually sold by the ton, so the result is shown in US tons, with an optional cost if you enter the price per ton.
Stone Wall Calculator
Tons of stone for a dry-stack or mortared stone wall, from length, height and thickness — plus cost.
Formula
Weight = L × H × T × (1 − voids %) × density
Cost = weight (tons) × price per ton
Where L = wall length, H = height, T = thickness, voids % = share of the wall volume that is air gaps or mortar, density = weight of solid stone per unit volume.
How the Calculation Works
Step 1: Multiply length, height and thickness to get the wall volume.
Step 2: Reduce it by the voids percentage to get the volume of actual stone.
Step 3: Multiply by density and convert pounds to US tons (2,000 lb).
Variables Explained
| Input | Meaning | Unit |
|---|---|---|
| Length, height, thickness | Wall dimensions | ft, in, m |
| Stone density | Weight of solid stone | lb/ft³, kg/m³ |
| Voids | Gaps between stones | % |
| Price per ton | Optional supplier price | $ per US ton |
Example Calculation
Given: wall 20 ft long, 3 ft high, 18 in thick; density 165 lb/ft³; 20% voids
Volume: 20 × 3 × 1.5 = 90 ft³ (≈ 3.33 yd³)
Stone volume: 90 × 0.8 = 72 ft³
Weight: 72 × 165 = 11,880 lb
Result: ≈ 5.94 US tons
Weight and Volume Conversion Table
| Unit | Equivalent |
|---|---|
| 1 US ton | 2,000 lb ≈ 907 kg |
| 1 metric ton | 1,000 kg ≈ 2,205 lb |
| 1 yd³ | 27 ft³ |
Material Estimation Notes
Density
Density varies by stone type. The calculator’s hint gives a typical range for common building stones; your supplier can give a figure for the stone you buy.
Voids
Rough fieldstone leaves more gaps than cut or flat stone. The voids percentage is a judgment call — higher for irregular stone, lower for tightly fitted or mortared work.
Coverage from suppliers
Many stone yards quote coverage in square feet of wall face per ton for a given thickness. If you have that figure, divide the wall face area by it as a cross-check.
Waste Factor Considerations
Stones that don’t fit, broken pieces and the need to choose shapes all add waste. Ordering a little extra is common; how much depends on the stone and the builder.
Frequently Asked Questions
How many tons of stone do I need for a wall?
Wall volume × (1 − voids) × density, converted to tons.
How much does a cubic foot of stone weigh?
It depends on the stone; enter the density for your material.
How thick should a dry stone wall be?
Dry-stack walls are generally wider at the base for stability; follow a design guide or professional advice for your wall height.
Does a mortared wall need less stone?
Mortar fills gaps, so the stone share of the volume can be higher or lower depending on joint size — adjust the voids percentage.
How do I convert tons to cubic yards?
Divide the weight by the density per cubic yard of the stone.