Lung Capacity (Predicted)

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Estimate predicted FVC and FEV1 based on NHANES III equations.

Individual Stats

Age

Height (cm)

Ethnicity

Estimated Predicted Values

Predicted FVC4.56Liters

Predicted FEV14.02Liters

FEV1 / FVC Ratio88%

These results represent the *expected* normal value for your demographics.

Spirometry results should be interpreted by a specialist. Values < 80% predicted may indicate underlying pathology.

About this calculator

Overview

Spirometry reference values (like FVC and FEV1) represent the volume of air a healthy person of a specific age, height, and ethnicity can exhale. These 'predicted' values are used to compare against actual patient results to diagnose conditions like COPD, asthma, or restrictive lung disease.

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Pro Tips

Invert your values if you use inches (1 inch = 2.54 cm).
NHANES III Ethnicities: Caucasian, African American, Mexican American.
Smokers and people with chronic exposure to pollutants usually have lower observed values than these predictions.

Fun Facts

"FEV1 is the volume of air exhaled during the first second of a forceful breath."
"FVC (Forced Vital Capacity) is the total volume of air that can be exhaled."
"A ratio of FEV1/FVC < 0.70 is often used to diagnose obstructive lung disease."
"Predicted lung volumes naturally decrease with age and increase with height."

Formula: NHANES III (Hankinson et al.) linear regression equations.