Density Calculator
Density (kg/m³)
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Density (g/cm³)
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Floats in Water?
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How to Calculate Density
Density is mass per unit volume: ρ = m/V. It tells you how much matter is packed into a given space. Water has a density of 1000 kg/m³ (1 g/cm³), making it the standard reference for comparing densities of other materials.
Objects with density less than water (< 1000 kg/m³) float, while denser objects sink. This principle, discovered by Archimedes, is fundamental to shipbuilding, material science, and geology.
Common densities: air ≈ 1.2 kg/m³, wood ≈ 500-900 kg/m³, aluminum ≈ 2700 kg/m³, iron ≈ 7874 kg/m³, gold ≈ 19300 kg/m³. Density helps identify materials, calculate weights, and design floating structures.
Frequently Asked Questions
What is the density formula?
ρ = m/V (mass divided by volume). SI units are kg/m³. CGS units are g/cm³.
What is the density of water?
Pure water at 4°C has a density of exactly 1000 kg/m³ or 1 g/cm³. This varies slightly with temperature.
Why do some things float?
Objects float when their density is less than the liquid they're in. Wood (≈600 kg/m³) floats in water (1000 kg/m³) but sinks in gasoline (≈720 kg/m³).
How do you find mass from density?
m = ρ × V. Multiply density by volume. If density is 7874 kg/m³ and volume is 0.1 m³, mass = 787.4 kg.