Enter the Tidal Volume and Expiratory Reserve Volume into the calculator to determine the Inspiratory Reserve Volume. This calculator can also evaluate any of the variables given the others are known.

Irv (Inspiratory Reserve Volume) Formula\

The following formula is used to calculate the Inspiratory Reserve Volume (IRV).



  • IRV is the Inspiratory Reserve Volume (liters) TV is the Tidal Volume (liters) ERV is the Expiratory Reserve Volume (liters)

To calculate the Inspiratory Reserve Volume, add the Tidal Volume to the Expiratory Reserve Volume. This will give you the total amount of air that can be inhaled into the lungs after a normal tidal volume inhalation.

What is a Irv (Inspiratory Reserve Volume)?

Inspiratory Reserve Volume (IRV) is a measure in pulmonary function testing that refers to the additional amount of air that a person can inhale after a normal inhalation. It is the maximum volume of air that can be inhaled beyond the point of a normal breath in, providing an indication of lung capacity and health. The average IRV values are about 1900 ml for women and 3100 ml for men.

How to Calculate Irv (Inspiratory Reserve Volume)?

The following steps outline how to calculate the Inspiratory Reserve Volume (IRV).

  1. First, determine the Tidal Volume (TV) in liters.
  2. Next, determine the Expiratory Reserve Volume (ERV) in liters.
  3. Next, use the formula IRV = TV + ERV to calculate the Inspiratory Reserve Volume.
  4. Finally, calculate the IRV.
  5. After inserting the variables and calculating the result, check your answer with the calculator above.

Example Problem:

Use the following variables as an example problem to test your knowledge.

Tidal Volume (TV) = 2 liters

Expiratory Reserve Volume (ERV) = 1.5 liters