Density Converter
Convert density between kg/m³, g/cm³, g/L, and lb/ft³.
What is Density?
Density is mass divided by volume, so its units are a mass unit over a volume unit. The metric pair kg/m³ and g/cm³ differ by exactly 1000 (water is about 1 g/cm³, which is 1000 kg/m³), while the imperial lb/ft³ is the unit US engineering drawings use.
How it works
Each unit is stored as a factor to kg/m³, built from a mass factor over a volume factor — 1 lb/ft³ is 0.45359237 kg over 0.028316846592 m³. Converting divides the two factors, so the metric and imperial sides are both exact rather than rounded constants.
- Enter your input. Type or paste your input into the field above — the tool responds instantly.
- Review the result. Output updates live as you type. Everything runs entirely in your browser.
- Copy or download. Use the Copy button to grab the result, or Download to save it as a file.
Examples
Water in SI and CGS
Enter 1 g/cm³ and read 1000 kg/m³ — the same density in the two systems most textbooks mix.
Common mistakes
Density vs specific gravity
Specific gravity is a ratio to water's density and has no units. Converting it as if it were kg/m³ gives an answer that is off by a factor of 1000.
Mixing g/cm³ and kg/m³
A density written without units is ambiguous: 1000 is water in kg/m³ and granite in g/cm³. Convert both values into one unit before comparing them.
Frequently asked questions
Which units are included?
kg/m³, g/cm³, kg/L, g/L, mg/L, lb/ft³, lb/in³, and lb per US gallon — the metric and imperial sets used in physics, chemistry and US engineering.
Why is 1 g/cm³ equal to 1000 kg/m³?
A gram is 1/1000 of a kilogram and a cubic centimeter is 1/1,000,000 of a cubic meter, so multiplying by 1000/1,000,000 and inverting gives the factor 1000.