Worked example

Al sample m=54.0 g, V=20.0 cm³ → ρ=2.70 g·cm⁻³.

Density

Relate mass and volume to characterize substances.

Equation

$\rho = \frac{m}{V}$

Inline: $\rho = \frac{m}{V}$$

Variables

Symbol	Quantity	Unit	Notes
$ρ$	density	g·cm⁻³	mass per unit volume
$m$	mass	g	measured mass
$V$	volume	cm³	measured volume

Conditions and limitations

Assumes uniform sample; temperature dependent.

Rearrangements

$m = \rho V$, $V = m/\rho$

Dimensional check: [M][L⁻³] ✓

Worked example

Al sample m=54.0 g, V=20.0 cm³ → ρ=2.70 g·cm⁻³.

Steps: write equation → substitute with units → check dimensional consistency → report with correct significant figures.

Common errors

• Confusing density with weight
• Using inconsistent volume units

Related resources

• matter-measurement topic
• Calculators — linked only when a real calculator implements this formula.
• Constants — sourced constants with version when values are required.

Sources

• NIST Physical Constants 2022 — CODATA.

Reviewed 2026-08-21 by Editorial Team; due 2027-08-21.