Final temperature of a mixture calculator

Enter the mass, specific heat and temperature of each substance to get the shared temperature at equilibrium. Suited to calorimetry and mixing hot and cold water.

Loading the tool…

Processing and privacy: The result is calculated inside your browser and your data is not sent to any server.

How to use it

  1. Enter mass of substance 1, specific heat of substance 1, temperature of substance 1, mass of substance 2, specific heat of substance 2 and temperature of substance 2.
  2. The result appears straight away and updates as you edit.
  3. Copy the result, or copy a link that keeps the same values to share it.

How it is calculated

T = (m₁c₁T₁ + m₂c₂T₂) / (m₁c₁ + m₂c₂), and the heat transferred is Q = m₁c₁ × (T₁ − T).

Example

Inputs: Mass of substance 1 = 1 kg, Specific heat of substance 1 = 4,184 J/(kg·K), Temperature of substance 1 = 80 °C, Mass of substance 2 = 2 kg, Specific heat of substance 2 = 4,184 J/(kg·K). Result: Final temperature: 40 °C; Heat lost by substance 1: 167,360 J.

Limits and caveats

  • It assumes an isolated system with no heat lost to the container or the air.
  • It does not apply if a phase change such as melting ice or boiling happens during mixing.

Questions about this tool

How do I mix hot and cold water?

Enter 4184 as the specific heat for both, and the result becomes a mass-weighted average.

Can I use liters instead of kilograms for water?

Approximately, yes. A liter of water has a mass close to 1 kg at ordinary temperatures.

Why does a hot metal piece cool so fast in water?

Water has a high specific heat, so it absorbs a lot of heat with only a small rise in temperature.