Cubic Feet to Pounds / Weight Converter

How to use the Cubic Feet to Pounds / Weight Converter

Enter a density that matches the material and condition. Select lb/ft³ or kg/m³, and select the output mass unit.
Choose volume-to-weight or weight-to-volume. Enter the known amount, material density and the matching mass and density units.
Select Calculate. Review the result and its working; if you change an input, calculate again before copying or sharing.

Weight equals volume times the stated density. For the reverse calculation, divide weight by density using matching units.

THE FORMULA Mass = volume × density; volume = mass ÷ density

Volume (ft³) or mass (selected unit): A numeric input used by the displayed calculation.
Material density: A numeric input used by the displayed calculation.

TRY IT ON PAPER

Use 1 ft³ of material and a density of 62.4 lb/ft³ to estimate its weight in pounds.

Answer: 62.4 lb. Density used: 62.4 lb/ft³.

A material has a mass of 1,000 kg and a stated density of 1,000 kg/m³. Select weight to volume and kilograms.

Answer: 35.314667 ft³. Density used: 62.427961 lb/ft³.

Is there a fixed cubic-feet-to-pounds factor?

No. Multiply volume by the relevant density. Different materials have different weights for the same volume.

Can I convert pounds back to cubic feet?

Yes. Select weight to volume, enter the mass and material density, and choose the mass unit used.

Match density to the material and condition being measured. Loose gravel, solid stone and wet soil do not share a single density.

The initial water density is an illustration, not a default for gravel, soil or wood. Moisture, composition and bulk packing can change density.

Density must match the material, moisture and packing state.

Divide weight by density in matching units to recover volume. Verify that the supplier density describes the material’s actual condition.