Pulmonary Function Test (PFT) Calculator
Pulmonary function testing is vital for assessing lung health. With this free, easy-to-use PFT calculator, you can instantly compute your key spirometry values—Forced Expiratory Volume in 1 second (FEV₁), Forced Vital Capacity (FVC), and the FEV₁/FVC ratio. Whether you’re a healthcare professional, respiratory therapist, or patient monitoring asthma, COPD, or other lung conditions, this tool helps you interpret spirometry data quickly and accurately.
Enter your raw measurements (in liters) below. The calculator will:
- Show your FEV₁ and FVC values.
- Compute the FEV₁/FVC ratio as a percentage.
- Provide a quick interpretation—normal, obstructive, or restrictive pattern.
How to Use This Calculator
1. Perform your spirometry test with proper calibration.
2. Record FEV₁ and FVC from the best of three attempts.
3. Enter values into the fields above and click Calculate.
4. Review your ratio and interpretation to determine lung function pattern.
Interpreting Your Results
The FEV₁/FVC ratio is a key marker:
- ≥70%: Typically normal lung function.
- <70%: Suggests obstructive disease (e.g., COPD, asthma).
Tips for Accurate Testing
- Ensure mouthpiece seal and correct posture.
- Repeat tests at least three times for consistency.
- Follow standardized protocols from CDC NIOSH.
Frequently Asked Questions
What is spirometry?
Spirometry measures airflow and volume during forced exhalation; it helps diagnose obstructive and restrictive lung diseases.
Can I use this without a clinician?
This calculator gives estimates. Always consult a healthcare professional for diagnosis and treatment.
Where can I learn more?
Read official guidelines at the American Lung Association.
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Munna Bhai
Digital Marketer/ Web App Developer & FB/Instagram Ads Expert