FEV1 percentile calculator for Canadians with cystic fibrosis
Lung function for individuals with CF is usually reported as a percentage of forced expiratory
volume in 1s (FEV1) in litres that would be seen in an individual without CF of the same age, sex
and height, referred to as FEV1pp. FEV1pp does not indicate how an individual compares to other
individuals with CF of the same age, sex and height; that is what this tool does.
If you enter your FEV1 in litres, sex, age and height in the spaces below, you will be returned
with a percentile. If, for example, you are returned the 97th percentile, that indicates that
only 3% of individuals with CF in Canada who are the same sex, age and height have better
Disclaimer: These percentiles are for individuals with Cystic Fibrosis and are estimates based on
the methodology outlined in
Kim et al. Reference Percentiles of FEV1 for the Canadian Cystic Fibrosis
Population: Comparisons Across Time and Countries. Thorax.
These tools do
not give professional advice; healthcare professionals who use this tool should exercise their own
clinical judgement when interpreting the information the tool provides. Non-medical professionals who
are using this tool, do so at their own risk. For medical concerns including decisions about
medications and other treatments, non-medical users should always consult their physician.