lb/ft³ to kg/m³ Converter
Convert pounds per cubic foot to kilograms per cubic meter — the imperial-to-SI density conversion. 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 lb/ft³ to kg/m³ 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 lb/ft³ | 16.0185 kg/m³ | pound per cubic foot to kilogram per cubic meter |
| 5 lb/ft³ | 80.0923 kg/m³ | pound per cubic foot to kilogram per cubic meter |
| 10 lb/ft³ | 160.1846 kg/m³ | pound per cubic foot to kilogram per cubic meter |
| 25 lb/ft³ | 400.4616 kg/m³ | pound per cubic foot to kilogram per cubic meter |
| 50 lb/ft³ | 800.9232 kg/m³ | pound per cubic foot to kilogram per cubic meter |
| 62.43 lb/ft³ | 1,000.0327 kg/m³ | pound per cubic foot to kilogram per cubic meter |
| 75 lb/ft³ | 1,201.3848 kg/m³ | pound per cubic foot to kilogram per cubic meter |
| 100 lb/ft³ | 1,601.8463 kg/m³ | pound per cubic foot to kilogram per cubic meter |
| 150 lb/ft³ | 2,402.7695 kg/m³ | pound per cubic foot to kilogram per cubic meter |
| 200 lb/ft³ | 3,203.6927 kg/m³ | pound per cubic foot to kilogram per cubic meter |
| 490 lb/ft³ | 7,849.0471 kg/m³ | pound per cubic foot to kilogram per cubic meter |
| 700 lb/ft³ | 11,212.9244 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
How many kg/m³ in a lb/ft³?
16.0185.
What is the density of water in lb/ft³?
62.43 lb/ft³.
What is concrete?
About 150 lb/ft³, or 2,400 kg/m³.
Where is lb/ft³ used?
US construction and materials specifications, particularly for concrete, timber and insulation.
What is steel in lb/ft³?
About 490 lb/ft³, which is 7,850 kg/m³.
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.