How to Calculate Minute Ventilation by Using Weight

Minute ventilation is a term used to describe the amount of air moved in and out of the airways of the lungs per minute. Minute ventilation is calculated by multiplying the tidal volume in mL per breath by the respiratory rate in breaths per minute to yield a value of mL per minute. The tidal volume of a normal individual at rest can be estimated as 7 mL per kg of body weight.

Instructions

• 1

  Determine the respiratory rate of the individual by counting the number of breaths taken in 15 seconds and multiplying by 4 to determine breaths per minute.

• 2

  Estimate the individual's tidal volume by multiplying his or her weight in kg by 7 mL per kg. For example, a person who is 70 kg will have a tidal volume of 490 mL.

• 3

  Calculate the minute ventilation by multiplying the respiratory rate by the tidal volume. For instance, a 70 kg individual with a respiratory rate of 12 breaths per minute and an estimated tidal volume of 490 mL per breath has a minute ventilation of 5,880 mL per minute, since 12 times 490 equals 5,880.