grams per cubic centimeter (g/cm3) to kilograms per liter (kg/L) conversion

What is the Gram per Cubic Centimeter?

The gram per cubic centimetre is a metric unit of density widely used in chemistry, materials science, and geology because most solids and liquids have convenient single- or double-digit values in these units.

Definition

One gram per cubic centimetre is one gram of mass in a volume of one cubic centimetre. Since a cubic centimetre is one millionth of a cubic metre and a gram is one thousandth of a kilogram, the unit equals exactly 1000 kilograms per cubic metre.

$$1\ \text{g/cm}^3 = 1000\ \text{kg/m}^3$$

It is numerically identical to the gram per millilitre and to the tonne per cubic metre.

Origin and History

The unit arose from the centimetre-gram-second (CGS) system introduced in the 19th century, in which it was the standard measure of density. It was historically anchored to water: the gram was originally defined so that one cubic centimetre of water at maximum density weighed almost exactly one gram, giving water a density near 1 g/cm³.

Law and Notable Facts

Though CGS has been superseded by SI, the gram per cubic centimetre remains the everyday unit for tabulating densities of materials. A substance with density less than 1 g/cm³ floats on water while a denser one sinks. Osmium and iridium, the densest naturally occurring elements, sit around 22.6 g/cm³.

Real-World Examples and Conversions

• Water at 4 °C: about 1.000 g/cm³ (1000 kg/m³).
• Aluminium: about 2.70 g/cm³; iron: about 7.87 g/cm³.
• Gold: about 19.3 g/cm³ (19300 kg/m³).
• 1 g/cm³ = 1000 kg/m³ = 1 g/mL = 1 kg/L.

What is the Kilogram per Liter?

The kilogram per liter is a metric unit of mass density, expressing how many kilograms of mass occupy one liter of volume. It is widely used in chemistry, brewing, and everyday contexts because water has a density very close to 1 kg/L.

Definition

One kilogram per liter equals one kilogram of mass distributed over a volume of one liter (one cubic decimeter). Because there are 1000 liters in a cubic meter, the value in SI base units is:

$$1\ \text{kg/L} = 1000\ \text{kg/m}^3$$

Numerically, 1 kg/L is identical to 1 g/mL and to 1 g/cm³, which makes it a convenient bridge between laboratory-scale and bulk measurements.

Origin and History

The unit follows directly from the metric system introduced in France in the 1790s, which defined the gram as the mass of one cubic centimeter of water at its temperature of maximum density (about 4 °C). This deliberate design fixed the density of water at essentially 1 kg/L, and the liter became the standard everyday metric volume.

Law and Notable Facts

The kilogram, liter, and cubic meter are all recognized in the SI (the liter as an accepted non-SI unit). Pure water at 4 °C has a density of about 0.99997 kg/L, historically taken as exactly 1 kg/L, which is why the near-unity value is no coincidence but a founding choice of the metric system.

Real-World Examples and Conversions

Whole cow's milk has a density of roughly 1.03 kg/L. Ethanol is about 0.789 kg/L, so it floats concepts of "lighter than water." Mercury is about 13.6 kg/L. To convert to pounds per US gallon, multiply by 8.345, so water (1 kg/L) is about 8.35 lb/gal.