Enter the temperature and masses of two different bodies of water into the calculator to determine the final water mixture temperature.

Water Temperature Formula

The following formula is used to calculate the final temperature of a water mixture. 

WT = (m1*T1 + m2*T2) / (m1+m2)
  • Where WT is the water temperature of the mixture when both are combind together
  • m1 and t1 are the mass and temperature of the first container of water
  • m2 and t2 are the mass and temperature of the second container of water

For this formula, the specific heat of the water is omitted because they are the same. If you have two substances with different specific heats, visit the final temperature calculator linked above.

To calculate the water temperature of a mixture, multiply the mass and temperature of the first container together and add it to the product of the mass and temperature of the second container. Finally, take that result and divide it by the sum of the masses of water of each container.

What is the final water temperature of a mixture?

Calculating the final water temperature fo a mixture of two or more separate bodies of water is done by adding together the multiplication of the mass and temperature of each body of water and then dividing by the sum of the masses.

Example Problem

How to calculate water temperature?

First, determine the mass of the first body of water. For this example, the first body of water is 200 grams.

Next, determine the temperature of the first body of water. This is measured to be 50C.

Next, determine the mass and temperature of the second body of water. In this example, the mass is 100 grams and the temperature is 40C.

Finally, calculate the water temperature when combined using the formula above:

WT = (m1*T1 + m2*T2) / (m1+m2)

WT = (200 * 50 + 100 * 40) / (100 + 200)

WT = 46.6667