what should my peak flow be

To determine your peak flow, you should use a peak flow meter, a portable device that measures your ability to push air out of your lungs. The peak flow meter measures how fast air comes out of your lungs when you exhale forcefully. It is important to measure your peak flow when you feel well to establish your normal or best peak flow. Your personal best peak flow is the highest number you can perform over a two-week period when your asthma is under good control. This number can be determined from predicted normal peak flow values for people of the same age and height. It is recommended to measure your peak flow rate close to the same time each day, and to keep a chart of your peak flow rates, discussing the readings with your healthcare provider. Your healthcare provider can also determine your peak flow number based on a personal baseline.