Density Physics Calculator

Solve for density, mass, or volume using the fundamental formula: ρ = m/V

Tip: Switch between calculation modes using the tabs below. All calculations use consistent units.

Density Formula

ρ = m/V

ρ = density, m = mass, V = volume

Common Material Densities

Water: 1 g/cm³
Iron: 7.87 g/cm³
Aluminum: 2.7 g/cm³
Gold: 19.3 g/cm³
Air: 0.0012 g/cm³
Oak Wood: 0.75 g/cm³

Understanding Density in Physics

What is Density?

Density (ρ) is a fundamental physical property defined as mass per unit volume. It describes how much matter is packed into a given space and is typically measured in kilograms per cubic meter (kg/m³) or grams per cubic centimeter (g/cm³).

Why Density Matters

Density determines whether objects float or sink in fluids (buoyancy), helps identify substances, and is crucial in material science, engineering, and fluid dynamics. It's an intensive property, meaning it doesn't depend on the amount of material.

Real-World Applications

  • Shipbuilding: Calculating buoyancy and displacement
  • Geology: Identifying mineral composition
  • Manufacturing: Quality control of materials
  • Meteorology: Understanding air masses and weather patterns

Density Calculation Examples

Example 1: Regular Solid

A brick measures 20cm × 10cm × 5cm and weighs 2.5kg. Calculate its density.

Solution: Volume = 20×10×5 = 1000cm³; Density = 2500g/1000cm³ = 2.5 g/cm³

Example 2: Liquid Measurement

250mL of an unknown liquid has a mass of 300g. What is its density?

Solution: 250mL = 250cm³; Density = 300g/250cm³ = 1.2 g/cm³

Example 3: Finding Mass

How much does 3m³ of concrete weigh if its density is 2400 kg/m³?

Solution: Mass = 2400 kg/m³ × 3m³ = 7200 kg

Frequently Asked Questions

How do I calculate density for irregular objects?

Use water displacement to find volume: Submerge the object in a graduated cylinder and measure the water level change. Then divide mass by this volume.

Why does ice float on water?

Ice has lower density (about 0.92 g/cm³) than liquid water (1 g/cm³) due to its crystalline structure that creates more space between molecules.

How does temperature affect density?

Generally, substances expand when heated (increasing volume), decreasing their density. Water is exceptional, being densest at 4°C.

What's the difference between density and specific gravity?

Specific gravity is the ratio of a substance's density to water's density (at 4°C), making it unitless. Density has units of mass per volume.

How accurate is this density calculator?

Our calculator provides precise calculations based on your inputs. For scientific work, always consider measurement precision and significant figures.