Does IRV include TV? 

Inspiratory capacity includes Tidal volume. Tidal volume is approximately 500 mL/inspiration. IRV is about 2500 – 3500 mL in the human lungs.

Kindly refer the link below:

https://www.meritnation.com/ask-answer/question/why-is-inspiratory-capacity-the-sum-of-tv-irv/breathing-and-exchange-of-gases/9997859