Peak flow meters

Three types of peak flow meters, showing mouthpiece and numbered scale on each.

A peak flow meter is a pocket-size device that measures peak expiratory flow (PEF), or how much air a person can quickly breathe out. To measure PEF, the person takes a deep breath and then blows into a tube on the peak flow meter as hard and as fast as possible. A scale on the device shows how much air is breathed out. This can be done at home.

Peak flow meters come in many shapes and sizes.

Current as of: November 14, 2022

Author: Healthwise Staff
Medical Review:
John Pope MD - Pediatrics
Adam Husney MD - Family Medicine
Elizabeth T. Russo MD - Internal Medicine
Caroline S. Rhoads MD - Internal Medicine
Lesley Ryan MD - Family Medicine