Density Calculator
Calculate density from mass and volume, mass from density and volume, or volume from density and mass. Supports g/cm³ and kg/m³.
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cm³
g/cm³
Density (g/cm³)
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Density (kg/m³) —
Mass (g) —
Volume (cm³) —
Extended More scenarios, charts & detailed breakdown ▾
g
cm³
Density (g/cm³)
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Density (kg/m³) —
Professional Full parameters & maximum detail ▾
g
cm³
g/cm³
Density (g/cm³)
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Density (kg/m³) —
Density (lb/ft³) —
Mass (g) —
Mass (kg) —
Volume (cm³) —
Relative Density (vs water 4°C) —
Floats in Water? —
How to Use This Calculator
- Select what to solve for: Density, Mass, or Volume.
- Enter the two known values.
- Results show the answer in multiple units.
Formula
ρ = m ÷ V | m = ρ × V | V = m ÷ ρ
where ρ = density (g/cm³), m = mass (g), V = volume (cm³)
Example
Example: mass = 270 g, volume = 100 cm³ → density = 2.70 g/cm³ (aluminum).
Frequently Asked Questions
- Density (ρ) = Mass (m) ÷ Volume (V). The three rearrangements are: ρ = m ÷ V (find density), m = ρ × V (find mass from density and volume), and V = m ÷ ρ (find volume from mass and density). Density is typically measured in grams per cubic centimeter (g/cm³) or kilograms per cubic meter (kg/m³). These units are equivalent: 1 g/cm³ = 1,000 kg/m³. For example, a 540 g aluminum block with volume 200 cm³ has density = 540 ÷ 200 = 2.70 g/cm³. Select the variable you want to solve for using the Solve For dropdown.
- Pure water has a maximum density of 1.000 g/cm³ at 4°C (39°F), which is 1,000 kg/m³ or 62.43 lb/ft³. Water density decreases slightly above and below 4°C — at 20°C (room temperature) it is 0.9982 g/cm³, and at 100°C (boiling) it drops to 0.9584 g/cm³. Ice is less dense than liquid water (0.917 g/cm³), which is why ice floats. Seawater is denser than fresh water (approximately 1.025 g/cm³) due to dissolved salts. These values make water a convenient reference: objects with density greater than 1 g/cm³ sink in fresh water; those less than 1 g/cm³ float.
- Dry air at sea level and 20°C (68°F) has a density of approximately 1.20 kg/m³ or 0.00120 g/cm³. Air density decreases with altitude: at 5,000 m elevation it is about 0.74 kg/m³, and at 10,000 m (typical cruising altitude) it is about 0.41 kg/m³. Higher temperatures lower air density; higher pressures increase it. Humid air is actually slightly less dense than dry air because water vapor (molar mass 18 g/mol) is lighter than nitrogen (28 g/mol) and oxygen (32 g/mol). Pilots and engineers use density altitude (air density adjusted for temperature) to calculate aircraft performance.
- Aluminum has a density of approximately 2.70 g/cm³ (2,700 kg/m³ or 168.5 lb/ft³). This is about one-third the density of steel (7.85 g/cm³), which is why aluminum is widely used in aerospace and automotive applications where weight savings are critical. Aluminum alloys vary slightly in density: 2024-T3 (aerospace alloy) = 2.78 g/cm³; 7075-T6 = 2.81 g/cm³; 6061-T6 = 2.70 g/cm³. For comparison: titanium = 4.51 g/cm³ (stronger than steel, lighter), magnesium = 1.74 g/cm³ (even lighter than aluminum), and carbon fiber composites = 1.5–1.6 g/cm³.
- Use water displacement (Archimedes method): fill a graduated container with enough water to submerge the object, record the initial water level, submerge the object, and measure the new water level. The volume of the object equals the increase in water level in milliliters (since 1 mL = 1 cm³). For example, if water rises from 200 mL to 247 mL after submerging a rock, the rock volume = 47 cm³. If the rock has a mass of 127 g, its density = 127 ÷ 47 = 2.70 g/cm³ (granite). Ensure the object is fully submerged and does not absorb water.