Density Calculator
Professional density calculator. Compute density, mass, or volume with unit conversions, geometry-assisted volume, and freight density class.
Interactive calculator
Choose the variable you know and let the tool compute the rest with consistent units.
Switching resets unit selections to the chosen system.
Select a material to fill the density input; you can modify it afterwards.
Freight density helper (LTL)
Results are rounded for clarity. SI values retain four decimal places for small numbers and two for larger ones.
How to Use This Calculator
Enter the quantities you know, choose the solve target, and the calculator converts everything to SI before displaying the result in multiple unit systems.
- Provide the mass and its unit, keeping consistent unit selections with the preferred system.
- Choose the volume input method. Enter the volume directly or use the box/cylinder helpers to derive cubic meters.
- If you are solving for mass or volume, give the density and pick the meaningful unit.
- Click Calculate to refresh results. The SI density is shown first alongside conversions and an optional freight class.
Methodology
All numeric inputs are converted to SI base units before computation (kg for mass, m³ for volume, and kg/m³ for density). The formula ρ = m / V governs every calculation; inverses are used when solving for mass or volume. Box and cylinder helpers convert dimensions by applying the standard geometric formulas, and conversions to imperial units use fixed, authoritative factors.
Glossary
- ρ (Density): Mass divided by volume with units such as kg/m³, g/cm³, or lb/ft³.
- m (Mass): Physical amount of matter. Accepts kg, g, lb, or oz.
- V (Volume): Space occupied—use m³, L, ft³, in³, or US gallons.
- L, W, H: Length, width, height for boxes.
- d, h: Diameter and height for cylinders.
- Freight class: Estimated NMFC class derived from density thresholds.
Example
Suppose you have 0.5 kg of liquid occupying 0.5 L (0.0005 m³). Compute density: $$\rho = \frac{0.5\;kg}{0.0005\;m^3} = 1000\;kg/m^3$$. The calculator then shows the equivalent 1 g/cm³, 1 g/mL, ≈62.43 lb/ft³, and ≈8.345 lb/gal.
Frequently Asked Questions
Is density the same as specific gravity?
No. Specific gravity compares a substance to a reference density and is unitless, while density carries units such as kg/m³.
Can I compute mass if I only know dimensions and density?
Yes. Use the box or cylinder helper to calculate volume, select Mass as the solve target, and supply density. The calculator performs m = ρ·V.
Which water density should I use?
Water is approx. 1000 kg/m³ at 4°C and ~998.2 kg/m³ at 20°C. Choose the value that matches your temperature conditions.
Why do I see very small numbers in lb/in³?
A cubic inch is tiny, so densities look small. Use lb/ft³ or lb/gal for more familiar magnitudes in US customary units.
What precision does the calculator use?
Internally it uses double-precision arithmetic. Results are rounded for readability, but the SI density retains four decimals for small magnitudes.
Is the freight class accurate?
The freight class is an estimate derived from NMFC density thresholds. Confirm the final class with your carrier because liability and handling affect the class.
Strumento sviluppato da Ugo Candido. Contenuti verificati e aggiornati per l'accuratezza al 19 gennaio 2026.