Density CalculatorFree online science calculator — instant results, no sign-up
Calculate density from mass and volume (ρ = m / V).
About the Density Calculator
The Density Calculator divides mass in grams by volume in cubic centimeters to find a material’s average density. It reports the result in g/cm³ and kg/m³ and estimates whether the material floats in water. With the default mass of 500 g and volume of 250 cm³, the density is 2 g/cm³, so the water-floating estimate is No.
- Mass (g)
- The mass of the sample in grams (g), with a default value of 500.
- Volume (cm³)
- The volume occupied by the sample in cubic centimeters (cm³), with a default value of 250.
Formula and method
ρ = m / V; ρ = 500 g / 250 cm³ = 2 g/cm³. Density in kg/m³ = density in g/cm³ × 1,000 = 2,000 kg/m³. Floats in water? Yes if ρ < 1 g/cm³; otherwise No.
- ρAverage density, calculated in g/cm³ when mass is in grams and volume is in cubic centimeters.
- mMass of the sample in grams (g).
- VVolume of the sample in cubic centimeters (cm³).
Divide the entered mass by the entered volume to obtain density in g/cm³. Multiply that result by 1,000 to convert it to kg/m³. Compare the density with an assumed water density of 1 g/cm³ to produce the floating estimate. For 500 g and 250 cm³, these operations give 2 g/cm³, 2,000 kg/m³, and No.
Worked example
These are the calculator's starting values and the results it actually produces for them.
Inputs
- Mass500 g
- Volume250 cm³
Results
- Density2 g/cm³
- In kg/m³2,000
- Floats in water?No
How to use the Density Calculator
- 1Enter the sample’s mass in Mass (g); keep 500 for the default example.
- 2Enter the corresponding sample volume in Volume (cm³); keep 250 for the default example.
- 3Check that both measurements describe the same sample and that volume is greater than zero.
- 4Read the density results: the default inputs give 2 g/cm³ and 2,000 kg/m³.
- 5Read Floats in water?: the default result is No because 2 g/cm³ exceeds the assumed water density of 1 g/cm³.
Reading your result
Density shows mass per unit volume: 2 g/cm³ means each cubic centimeter contains an average of 2 grams. In kg/m³ expresses the same density in SI units, so the default output of 2,000 means 2,000 kg/m³. Floats in water? is a simplified density comparison: No for the default example means the sample is denser than water and is expected to sink under the stated assumptions.
Limitations
Volume must be greater than zero, and negative mass is not physically meaningful for this calculation. Accuracy depends on the mass and volume measurements; the result is an average density and does not reveal internal variations. The floating estimate assumes water has a density of 1 g/cm³ and ignores surface tension, dissolution, and other interactions. Temperature and salinity affect water density. For hollow or porous objects, the entered mass and volume must account appropriately for trapped air and water entry. A density exactly equal to water’s indicates neutral buoyancy rather than a tendency to rise, even though the binary rule reports No.
Common questions
Why do 500 g and 250 cm³ give a density of 2 g/cm³?+
Density is mass divided by volume. Dividing 500 by 250 gives 2, and dividing grams by cubic centimeters gives g/cm³.
Why does the kg/m³ output show 2,000 rather than 2?+
One g/cm³ equals 1,000 kg/m³. Multiplying the default density of 2 g/cm³ by 1,000 gives 2,000 kg/m³; the physical density has not changed.
Can I enter a volume measured in milliliters?+
Yes. One milliliter equals one cubic centimeter, so a measured volume in mL can be entered with the same numerical value in Volume (cm³).
Does No under Floats in water? guarantee that an object will sink?+
No. It is a simplified comparison with water at 1 g/cm³. The default density of 2 g/cm³ predicts sinking, but trapped air, surface tension, and how the object’s volume is measured can affect actual behavior.
Does the calculator save my information?+
Calculations run in your browser. While signed in, inputs and results are automatically recorded in account history; saving a result creates a separate saved record.
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Results are estimates for informational purposes and are not financial, medical or legal advice.