Children's Asthma Peak Flow Calculator

Your child's results

Because your child's height is , their estimated peak flow is .

About asthma

Asthma is a long-term (chronic) disease. Making sure that your child’s asthma is under control is a team effort. Your child and their caregivers are important team members.

One of the key parts of controlling asthma is having an Asthma Action Plan. You will develop this plan with the help of your child’s healthcare provider. Each person who cares for your child will need to have a copy of this plan. The plan is just for your child. Don’t use a plan created for someone else.

An Asthma Action Plan gives step-by-step instructions on what to do if your child has asthma symptoms. The plan helps reduce or prevent asthma flare-ups. It also helps keep your child out of the ER and the hospital. The plan tells you and your child what symptoms to watch for. It tells you how to treat those symptoms right away. This will also help stop flare-ups from getting worse. The plan will also tell you when to seek emergency care.

Part of your child’s Asthma Action Plan is watching their peak flow. You need to know how to use a peak flow meter. You also need to know what to do based on the meter’s readings.

Using the peak flow meter

Check your child's peak flow measurement when the following symptoms appear, unless your child's healthcare provider tells you otherwise:

• Coughing
• Wheezing
• Shortness of breath

Talk with your child's healthcare provider before measuring your child's personal best peak flow number. They may have other instructions or suggestions, based on your child's condition. Also show the provider how you or your child uses the peak flow meter. This will help you be certain that you are using correctly.

What are asthma action zones?

Your child’s Asthma Action Plan tells you what the values should be for your child's Green, Yellow and Red Zones. These zones tell you how much your child's daily peak flow differs from their personal best. It is important to follow your child’s Asthma Action Plan when his or her peak flow measurement falls in each of these zones. Always follow your child's Asthma Action Plan when acting on your child's peak flow measurements.

Here is a breakdown of each zone:

• The Green Zone is 80% to 100% of your child's personal best. It is a sign that your child's asthma is in good control. It means your child currently has no symptoms of asthma. Your child should continue to take their medicine as usual.
• The Yellow Zone is 50% to 80% of your child's personal best. The Yellow Zone number is your child's caution signal. It means your child needs to take their quick-relief medicine. The instructions will be in your child's Asthma Action Plan. The Yellow Zone also means your child's asthma may not be in good control. After your child recovers, call your healthcare provider to see if your child needs to change or take more of their daily medicines.
• The Red Zone is less than 50% of your child's personal best. The Red Zone number is your child's emergency signal. Your child should take or take more of their quick-relief medicine right away. Follow the instructions in your child's Asthma Action Plan. Then call your child's healthcare provider to find out what to do. If your child's peak flow range does not return to the Yellow or Green Zone within the time expected, call 911. Also call 911 if your child’s Red Zone symptoms get worse.

Note: The numbers may be different for children ages 5 to 11. Talk with your child’s healthcare provider to find what peak flow ranges are normal. Follow the peak flow instructions in your child’s Asthma Action Plan.