密度
About Density Conversion
Density measures mass per unit volume—how much "stuff" is packed into a given space. It's a fundamental physical property that determines whether materials float or sink, affects structural load calculations, influences sound transmission through materials, and is essential in chemistry, materials science, manufacturing, and engineering. Density varies with temperature and pressure, particularly for gases, which is why specifications often include reference conditions.
The SI unit is kilograms per cubic meter (kg/m³), but grams per cubic centimeter (g/cm³) is widely used in chemistry and materials science because water's density is conveniently 1 g/cm³. In US construction and HVAC, pounds per cubic foot (lb/ft³) remains standard. Water's density (1 g/cm³ = 1000 kg/m³ = 62.4 lb/ft³ at 4°C) serves as the universal reference point—materials less dense than water float, denser materials sink.
Our converter handles all standard density units for scientific and engineering applications, from comparing material properties to calculating shipping weights.
Common Density Conversions
| From | To | Multiply By |
|---|---|---|
| kg/m³ | g/cm³ | 0.001 |
| g/cm³ | kg/m³ | 1000 |
| kg/m³ | lb/ft³ | 0.06243 |
| lb/ft³ | kg/m³ | 16.018 |
| g/cm³ | lb/ft³ | 62.43 |
| lb/ft³ | g/cm³ | 0.01602 |
| kg/L | kg/m³ | 1000 |
| kg/m³ | kg/L | 0.001 |
| lb/gal (US) | kg/m³ | 119.83 |
| kg/m³ | lb/gal (US) | 0.008345 |
Density Unit Reference
Kilogram per cubic meter (kg/m³) – The SI unit of density, standard for all scientific work and international engineering. Water = 1000 kg/m³ at 4°C (maximum density). Air at sea level ≈ 1.225 kg/m³. This large-scale unit is practical for bulk materials—concrete is about 2400 kg/m³, which means a cubic meter weighs 2.4 tonnes.
Gram per cubic centimeter (g/cm³) – The most common unit in chemistry, materials science, and geology. Numerically equals kg/L, making mental math easy. Water = 1 g/cm³ provides an intuitive reference. Most metals range from 2.7 (aluminum) to 19.3 (gold). Materials databases typically report density in g/cm³.
Pound per cubic foot (lb/ft³) – US customary unit widely used in construction, HVAC, shipping, and industrial applications. Water ≈ 62.4 lb/ft³. Concrete ranges from 100-150 lb/ft³ depending on type. Essential for calculating structural loads and shipping weights in American engineering.
Kilogram per liter (kg/L) – Convenient for liquids and directly relates volume to weight. Numerically equal to g/cm³. 1 kg/L = 1000 kg/m³. Gasoline is about 0.75 kg/L; milk is about 1.03 kg/L. Useful for calculating how much a tank of liquid weighs.
Pound per gallon (lb/gal) – Common for liquids in the US, especially fuels and chemicals. Water ≈ 8.34 lb/gal (US gallon) or ~10 lb/gal (Imperial gallon). Gasoline is about 6.3 lb/gal. Important for vehicle fuel calculations and chemical handling.
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