A peak flow meter is used to measure your peak expiratory flow rate (PEFR). PEFR describes how quickly your lungs expel air during a forceful exhalation after you fully inhale.

A peak flow meter is a handheld device that measures airflow rate and can help those with respiratory conditions like asthma monitor their condition.

The peak expiratory flow rate test measures how fast a person can exhale. It is commonly performed at home with a device called a peak flow monitor.