Density Conversions

Convert between the density units used in chemistry, materials, food and engineering: SI (kg/m³), lab (g/mL, g/cm³), process (kg/L) and US customary (lb/ft³, lb/in³). Includes specific gravity.

Base definition: 1 g/cm³ = 1 g/mL = 1000 kg/m³ = 1 kg/L. 1 lb/ft³ = 16.018463 kg/m³. 1 lb/in³ = 27,679.90471 kg/m³. 1 oz/in³ = 1,729.994044 kg/m³.

Water (≈ 4°C):

1000 kg/m³

1 g/cm³

62.428 lb/ft³

Current result in base (kg/m³):

1000.0000 kg/m³

Quick table (common materials)

Material kg/m³ g/cm³ lb/ft³
Water (approx)10001.0062.43
Sea water10251.0364.0
Ethanol7890.78949.3
Aluminum27002.70168.5
Steel78507.85489.1

How the density converter works

We use kg/m³ as the internal base. Every unit you enter is first converted to kg/m³, then back out to the target unit. This keeps the math consistent and matches common reference tables.

Formulas

base (kg/m³) = value × factorToKgM3[sourceUnit]

target = base (kg/m³) ÷ factorToKgM3[targetUnit]

Example: 1.2 g/cm³ → lb/ft³

1.2 g/cm³ = 1.2 × 1000 = 1200 kg/m³

lb/ft³ = 1200 ÷ 16.018463 = 74.9 lb/ft³

What about specific gravity?

Specific gravity (SG) is just “how many times as dense as water”. Since water is ≈ 1000 kg/m³, we use:

density (kg/m³) = SG × 1000

SG = density (kg/m³) ÷ 1000

FAQ

1. Do temperature and salinity matter?

Yes, especially for liquids. But for most day-to-day conversions, using the nominal densities (like 1000 kg/m³ for water) is perfectly fine.

2. Can I use this for bulk densities (soil, powders)?

Yes, just enter the measured bulk density in whatever unit you have and convert to the unit you need — the tool doesn’t assume a material.

3. Why are g/cm³ and g/mL the same?

Because 1 cm³ = 1 mL. So 1 g/cm³ = 1 g/mL.