FEV₁ % Predicted calculator
Result
1198% predicted
Normal
Predicted: 0.21 L (NHANES III).
How to use it
- 1
Post-bronchodilator spirometry. Best of 3 efforts. Compare to reference equations for age, sex, height.
- 2
FEV₁ ≥80% predicted = normal. 70–79% borderline; <70% with low FEV₁/FVC = obstruction.
- 3
GOLD staging. Use % predicted for GOLD 1–4 after obstruction confirmed.
When to use it
- COPD diagnosis and staging
- Spirometry is the gold standard — cannot diagnose COPD on symptoms alone.
- Asthma severity
- FEV₁ <70% + reversibility ≥12% and ≥200 mL = asthma.
- Pre-operative lung function
- Predicts post-operative respiratory complications, especially before pneumonectomy.
A reference for clinicians and students, not medical advice. A score supports a decision; it does not make one. Check every result against the patient in front of you and your local protocol.
At a glance
- Specialty
- Pulmonology
- Inputs
- 4
- Type
- Formula
