Calculate average temperature rate, final temperature, or elapsed time in Celsius, Fahrenheit or kelvin, with optional mass, specific heat, sensible heat and average net thermal power. Positive rates heat and negative rates cool.

Positive temperature change heats; negative change cools. Elapsed time must be greater than zero.

Sensible heat and net power

Enter both mass and specific heat to include energy; leave both blank to omit it.

Use a suitable average across the temperature range, with no phase change.

Heating Rate Formula

The examples below calculate average temperature change per unit time. This temperature rate is different from heat-transfer power in watts.

HR = dT / t
  • Where HR is the Heating Rate (°F/min)
  • dT is the total change in temperature (°F) 
  • t is the total time (min) 

To calculate the average temperature rate, divide final minus initial temperature by a positive elapsed time. Equal temperatures give zero rate. Final-temperature and time predictions assume a constant signed rate; a zero rate cannot reach a different target. If the target equals the start and the rate is zero, elapsed time is not uniquely determined. Optional sensible heat uses Q = mass × specific heat × temperature change, with suitable average specific heat, uniform temperature and no phase change. Average net power is Q divided by elapsed time; it is not an electrical heater rating.

How to Calculate Heating Rate?

The following example problems outline how to calculate Heating Rate.

Example Problem #1:

  1. First, determine the total change in temperature (°F).
    • The total change in temperature (°F) is given as 40; for example, use 32 °F initially and 72 °F finally. Select °F/min as the result rate unit.
  2. Next, determine the total time (min).
    • The total time (min) is provided as 20.
  3. Finally, calculate the Heating Rate using the equation above: 

HR = dT / t

The values provided above are inserted into the equation below and computed.

HR = 40 / 20 = 2 (°F/min)


Example Problem #2: 

For this problem, the variables required are provided below:

total change in temperature (°F) = 60

total time (min) = 5

Test your knowledge using the equation and check your answer with the calculator.

HR = dT / t = ?