grams per cubic centimeter (g/cm3) to grams per milliliter (g/mL) 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Though CGS has been superseded by SI, the gram per cubic centimetre remains the everyday unit for tabulating densities of materials.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 Gram per Milliliter?

The gram per millilitre is a metric density unit common in medicine, pharmacy, cooking, and laboratory work, where liquid volumes are naturally measured in millilitres.

Definition

One gram per millilitre is one gram of mass in one millilitre of volume. Because one millilitre is defined as exactly one cubic centimetre, the gram per millilitre is identical to the gram per cubic centimetre and equals 1000 kilograms per cubic metre.

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

Origin and History

The unit follows from the metric definitions of the gram and the litre established during the French Revolution, when the litre was fixed as one cubic decimetre and the gram tied to the mass of water. A 1964 redefinition made the litre exactly equal to 1000 cm³, so the millilitre coincides precisely with the cubic centimetre and g/mL with g/cm³.

Law and Notable Facts

The gram per millilitre is convenient because water has a density very close to 1 g/mL near room temperature, allowing quick mental conversion between the mass and volume of aqueous solutions. Drug concentrations, blood-test results, and reagent strengths are routinely reported in g/mL or its subunit mg/mL.

Real-World Examples and Conversions

• Water at room temperature: about 1.00 g/mL.
• Whole milk: roughly 1.03 g/mL.
• Ethanol: about 0.789 g/mL, so it floats-mixes with water.
• 1 g/mL = 1 g/cm³ = 1000 kg/m³ = 1000 mg/mL.