Bulk Material Calculator - Material Weight

Stone Weight Calculator

Estimate the weight of a solid cut-stone piece from its dimensions, shape factor, quantity, and solid density.

Reviewed: September 24, 2026

Calculate a solid stone piece

Measure a cut block or use its bounding dimensions. The calculator applies a stated shape factor, solid-stone density, and piece count; it does not use loose aggregate tons per cubic yard.

A shape factor reduces the measured bounding-box volume for an irregular piece. It is an explicit approximation, not a substitute for displacement measurement.

The 2,700 kg/m³ starting value is a granite-like solid-density example. Replace it with documented data for the actual stone; do not enter loose aggregate bulk density.

Large landscape boulder suspended above a platform scale with measuring tape nearby

Formula used

Total mass = length × width × height × unit conversion × shape factor × solid density × quantity

Reference basis: length, volume, kilogram, pound, and short-ton conversions follow the NIST SI conversion tables. Solid density must come from a material data sheet, fabricator, laboratory result, or other documented source for the stone being estimated. Read the methodology and limits.

Worked cut-stone example

Example values: a 36 × 24 × 18 in rectangular piece has a 9.00 ft³ volume. At a documented 2,700 kg/m³ solid density and a 1.00 shape factor, its estimated mass is about 688 kg, 1,517 lb, or 0.758 short ton.

Choosing and bounding the shape factor

A shape factor is the estimated fraction of the measured rectangular envelope actually occupied by stone. Use 1.00 for a rectangular cut block. For an irregular piece, calculate a range rather than presenting one guessed factor as exact: with the 36 × 24 × 18 in envelope above, factors of 0.70 and 0.52 give about 1,062 lb and 789 lb, compared with the 1,517 lb rectangular-envelope upper estimate. A measured volume method can improve the estimate for a manageable piece, but hidden voids and density variation remain.

When a trailer, hoist, crane, floor, or other load limit matters, obtain a scale ticket or documented fabricator weight. Do not select lifting equipment from a shape-factor estimate.

Solid pieces are not bulk aggregate

This tool estimates an individual solid piece. Use the cubic-yard or tonnage calculator for loose stone, because air gaps make bulk density fundamentally different from solid mineral density.

Shape and lifting limits

Irregular outlines, hidden voids, fractures, porosity, and moisture change actual mass. When handling limits matter, obtain a scale ticket or fabricator weight instead of relying on dimensions.

Questions specific to this calculation

Can I use tons per cubic yard for a boulder?

No. This calculator expects solid density in kg/m³. Tons per cubic yard for delivered aggregate includes void space and is not a solid-stone density.