Stone Wall Calculator

How it works

wall volume = length × height × thickness · stone = volume × stone fraction (0.70 mortared, 0.80 dry) × density × (1 + waste) · loose volume = solid ÷ 0.6 · mortar = 30% of volume, 350 kg cement per m³ (1:4)

Stone walls are estimated by volume. In mortared rubble masonry (mampostería) roughly 70% of the wall is stone and 30% mortar; a dry stone wall is about 80% stone once the small hearting stones that fill the core are included. Solid stone weighs 2.3–2.7 t/m³, so a dry wall typically takes about a tonne of stone per square metre of face for every 40–50 cm of thickness. Stone delivered loose by the truckload has about 40% voids, so order around 1.7 m³ of loose stone for each m³ of solid stone. A 1:4 cement–sand mortar uses about 350 kg of cement and 1.05 m³ of sand per m³.

Worked example

A 10 m mortared rubble wall 1.2 m high and 50 cm thick is 6.00 m³. About 70% is stone: 6 × 0.70 × 1.10 = 4.62 m³ of solid fieldstone × 2.6 t/m³ = 12.01 t, or 7.70 m³ of loose stone to order (1.00 t per m² of face). The 30% of mortar is 1.98 m³ with waste, needing 14 bags of 50 kg cement for a 1:4 mix and 2.08 m³ of sand.

Sources: Dry Stone Walling Association — Building a wall · USDA Forest Products / engineering densities of rock (Engineering ToolBox)

Frequently asked questions