How to Calculate Respiration

Doctor examining patient with stethoscope

Knowing how to calculate respiration is one of the most basic skills for anyone who works directly with patients, from caregivers to physicians. The rate of a person's respiration is indicative of many conditions, from pneumonia to shock to thoracic injury, and the information can be used to save a person's life. Done correctly, calculating respiration can be performed quickly and easily.

Make sure your patient is in a comfortable position, either sitting or lying down. For best results, they shouldn't be talking or moving.

Note your patient's age, condition and recent activity. Generally, children will breathe faster than adults, and those who have just completed exercise will breathe faster than when they are resting. Significantly overweight people and those who have respiratory ailments may also breathe faster and shallower than normal for those their age. Drugs and emotional states also affect respiratory rates.

Mark on your watch a start time with the position of the second hand. It's easiest to mark the start of your count when the hand ticks to 12, 3, 6 or 9.

Count your patient's breaths for 15 seconds Do this by watching the patient's abdomen rise and fall. Each rise and fall counts as one breath. Monitor the position of the second hand on your watch and stop after it makes a quarter of a revolution around the dial.

Multiply the number you get by four, and that should be the approximate number of breaths per minute.


Calculating respiratory rate is done best when the patient is not aware you are watching them breathe, as they tend to change the rate of respiration when they become self-conscious. Respiration is counted as part of vital signs --temperature, blood pressure, pulse and respiration - and are usually taken right after pulse while the caregiver is still holding the patient's wrist.

Respiratory calculation can also be done via stethoscope if the caregiver is monitoring how the patient's lungs are functioning. They can also be counted without touching the patient.

Counting over 30 seconds and multiplying by two, or counting over 60 seconds is more accurate than counting over 15 seconds. If your patient seems to be breathing very slowly, count breaths over a longer period of time for better accuracy.