Respiratory Volumes & Capacity

Tidal volume

The volume of one breath during Passive breathing.

TV

tidal volume (abbreviation)

Inspiratory Reserve Volume

the amount of air that can be Inspired forcibly

IRV

inspiratory reserve volume (abbreviation)

Expiratory Reserve Volume

The amount of air that can be Expelled from the lungs forcibly (after tidal expiration)

ERV

Expiratory Reserve Volume (abbreviation)

residual volume

The remaining air in the lungs (even after forced expiration) that keeps the lungs from collapsing.

RV

residual volume (abbreviation)

inspiratory capacity

total amount of air that can be inspired after tidal expiration.

IC

inspiratory capacity (abbreviation)

formula for inspiratory capacity

IC = TV + IRV

Functional Residual Capacity

the amount of air remaining in the lungs after tidal expiration.

FRC

Functional Residual Capacity (abbreviation)

formula for Functional Residual Capacity

FRC = ERV + RV

vital capacity

total amount of exchangeable air

VC

vital capacity (abbreviation)

vital capacity formula

VC = TV + IRV + ERV

Total Lung Capacity

Sum of ALL lung volumes (not capacities)

TLC

Total Lung Capacity (abbreviation)

Total Lung Capacity formula

TLC = VC + RV