Density Calculator: Compute Material Density with Mass, Volume & Conditions

How to use the tool

1 – Fill in the fields

• Mass: Type the number, pick a unit.
  Example A: 1.2 kg.
  Example B: 2 lb.
• Volume: Enter the space the substance occupies.
  Example A: 800 mL.
  Example B: 0.1 ft³.
• Temperature & Pressure (optional): Needed for gases only, choose °C/°F/K and Pa/kPa/atm/mmHg.

2 – Understand the math

The core formula is $$\rho=rac{m}{V}$$ where m is mass and V is volume.

• Unit changes
  g → kg: divide by 1 000.
  mL → m³: divide by 1 000 000.
  ft³ → m³: multiply by 0.028 316 8.
• Gas option uses $$\rho=rac{P\,M}{R\,T}$$ with P pressure, T absolute temperature, M molar mass, R = 8.314 J·mol⁻¹·K⁻¹.

3 – Example calculations

• Liquid sample
  1.2 kg / 0.000 8 m³ = 1 500 kg/m³.
• Imperial input
  2 lb = 0.907 kg, 0.1 ft³ = 0.002 832 m³.
  Density = 0.907 / 0.002 832 ≈ 321 kg/m³.

Quick-Facts

• Water density: 997 kg/m³ at 25 °C (NIST Chemistry WebBook, 2023)
• Standard air density: 1.225 kg/m³ at 15 °C, 101.325 kPa (NASA Atmosphere Model, 1976)
• Gold density: 19 300 kg/m³ (CRC Handbook, 2022)
• SI unit for density is kg/m³ (BIPM SI Brochure, 2019)

FAQ

What is density?

Density equals mass divided by volume; it shows how much matter occupies a given space (BIPM SI Brochure, 2019).

How does temperature affect gas density?

Raising temperature lowers gas density because molecules spread apart; a 10 °C rise drops air density ≈ 1.9 % (NASA, 1976).

Which unit conversions does the calculator handle?

It converts g↔kg, lb↔kg, oz↔kg and L, mL, cm³, ft³, in³↔m³ automatically.

How can you tell if an object floats?

If its density is below the fluid’s, buoyancy wins and it floats; otherwise it sinks (Archimedes’ Principle, Ancient Greece).

Does pressure change liquid density significantly?

Liquids compress little; a 100 bar rise changes water density by ~0.5 % (Engineering Toolbox, URL).

How precise is the result?

The tool returns four-decimal accuracy, adequate for lab work and design tolerances (ISO 5725-1, 2019).

Can you use it for mixtures?

Yes—input total mass and total volume to get bulk density; individual components remain unresolved (Perry’s Handbook, 2021).

How do I convert kg/m³ to g/cm³?

Divide by 1 000: “1 000 kg/m³ = 1 g/cm³” (NIST, 2023).