Enter the volume before boil (mL), the volume after boil (mL), and the time of boil (min) into the Boil Off Rate Calculator. The calculator will evaluate the Boil Off Rate. 

Boil Off Rate Formula

The following formula is used to calculate the Boil Off Rate. 

BOR = (V1 - V2) / T
  • Where BOR is the Boil Off Rate (mL/min)
  • V1 is the volume before boil (mL) 
  • V2 is the volume after boil (mL) 
  • T is the time of boil (min) 

To calculate the boil off rate, subtract the volume after boil from the volume before boil, then divide by the time.

How to Calculate Boil Off Rate?

The following two example problems outline the steps and information needed to calculate the Boil Off Rate.

Example Problem #1

  1. First, determine the volume before boil (mL).
    • The volume before boil (mL) is calculated to be : 30.
  2. Next, determine the volume after boil (mL).
    • The volume after boil (mL) is measured to be: 20.
  3. Next, determine the time of boil (min).
    • The time of boil (min) is found to be: 5.
  4. Finally, calculate the Boil Off Rate using the formula above: 

BOR = (V1 – V2) / T

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

BOR = (30 – 20) / 5 = 2.00 (mL/min)


Example Problem #2

The variables required for this problem are provided below:

volume before boil (mL) = 60

volume after boil (mL) = 50

time of boil (min) = 2

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

BOR = (V1 – V2) / T = (mL/min)