Density Converter
Convert kg/m³, g/cm³, kg/L, lb/ft³ and lb/gal — densities of water, concrete, steel, fuels and building materials. Results update as you type; exact factors shown.
One pound per cubic foot is 16.0185 kilogram per cubic meter — see the exact factor, not a rounded rule of thumb.
How the density converter works
Density converts through kg/m³. 1 g/cm³ = 1 kg/L = 1,000 kg/m³ (water at 4 °C). 1 lb/ft³ = 16.0185 kg/m³ and 1 lb/US gal = 119.83 kg/m³. Concrete is about 2,400 kg/m³, steel 7,850 kg/m³, petrol about 740 kg/m³.
The US uses customary units (US gallon, short ton, °F) in daily life; NIST SP 811 gives the exact SI factors.
Common density conversions
| From | To | Units |
|---|---|---|
| 1,000 kg/m³ | 62.428 lb/ft³ | kilogram per cubic meter to pound per cubic foot |
| 1 g/cm³ | 1,000 kg/m³ | gram per cubic centimeter to kilogram per cubic meter |
| 1 lb/ft³ | 16.0185 kg/m³ | pound per cubic foot to kilogram per cubic meter |
| 2,400 kg/m³ | 149.8271 lb/ft³ | kilogram per cubic meter to pound per cubic foot |
| 7,850 kg/m³ | 7.85 g/cm³ | kilogram per cubic meter to gram per cubic centimeter |
| 1 lb/US gal | 0.1198 kg/L | pound per US gallon to kilogram per liter |
| 0.92 g/cm³ | 57.4337 lb/ft³ | gram per cubic centimeter to pound per cubic foot |
| 1 t/m³ | 1,000 kg/m³ | tonne per cubic meter to kilogram per cubic meter |
| 1 lb/in³ | 27.6799 g/cm³ | pound per cubic inch to gram per cubic centimeter |
| 62.4 lb/ft³ | 999.5521 kg/m³ | pound per cubic foot to kilogram per cubic meter |
Units in this converter and their exact factors
| Unit | Symbol | One unit in kilogram per cubic meters |
|---|---|---|
| kilogram per cubic meter | kg/m³ | 1 kilogram per cubic meter |
| gram per cubic centimeter | g/cm³ | 1,000 kilogram per cubic meter |
| gram per milliliter | g/mL | 1,000 kilogram per cubic meter |
| kilogram per liter | kg/L | 1,000 kilogram per cubic meter |
| pound per cubic foot | lb/ft³ | 16.018463374 kilogram per cubic meter |
| pound per cubic inch | lb/in³ | 27,679.9047102 kilogram per cubic meter |
| pound per US gallon | lb/US gal | 119.826427317 kilogram per cubic meter |
| ounce per cubic inch | oz/in³ | 1,729.99404 kilogram per cubic meter |
| tonne per cubic meter | t/m³ | 1,000 kilogram per cubic meter |
FAQFrequently asked questions about density conversion
What is the density of water?
1,000 kg/m³ (1 g/cm³) at 4 °C; 998 kg/m³ at 20 °C; 62.4 lb/ft³.
How do I convert g/cm³ to kg/m³?
Multiply by 1,000.
What is the density of concrete?
About 2,400 kg/m³ (150 lb/ft³) for normal-weight concrete.
How many kg/m³ is 1 lb/ft³?
16.0185 kg/m³.
Why is density in kg/L the same number as g/cm³?
Because a liter is 1,000 cm³ and a kilogram is 1,000 g — the factors cancel.
Where these figures come from
- BIPM — The International System of Units (SI Brochure, 9th edition) — definitions of the base and derived units.
- NIST Special Publication 811 — Guide for the Use of the International System of Units — the exact conversion factors used here.
- National Institute of Standards and Technology (NIST) — United States's national measurement authority.
Last checked: September 2026. Conversion factors are fixed by definition and do not change with tax years or regulations.