FEV1/FVC Ratio Calculator
Determines the ratio of the forced expiratory volume in the first second to the forced vital capacity of the lungs.
Refer to the text below the tool for more information about the parameters involved.
The FEV1/FVC ratio is the ratio of the forced expiratory volume in the first one second to the forced vital capacity of the lungs.
The normal value for this ratio is above 0.75. Values lower than 0.70 are suggestive of airflow limitation with an obstructive pattern whilst in restrictive lung diseases, the FEV1/FVC ratio is normal or high.
Formulas
FEV1 = Race x 1.08 x [(0.0395 x Height) - (0.025 x Age) - 2.6]FVC = Race x 1.15 x [(0.0443 x Height) - (0.026 x Age) - 2.89]FEV1/FVC Ratio = FEV1 / FEVC
Interpretation
FEV1/FVC Ratios <70% are indicative of chronic obstructive pulmonary disease (COPD) or lower than 65% in patients older than 65 years.
Send Us Your Feedback
Steps on how to print your input & results:
1. Fill in the calculator/tool with your values and/or your answer choices and press Calculate.
2. Then you can click on the Print button to open a PDF in a separate window with the inputs and results. You can further save the PDF or print it.
Please note that once you have closed the PDF you need to click on the Calculate button before you try opening it again, otherwise the input and/or results may not appear in the pdf.
FEV1/FVC Ratio Explained
The FEV1/FVC ratio (Tiffeneau-Pinelli index) is the ratio of the forced expiratory volume in the first one second to the forced vital capacity of the lungs.
Forced expiratory volume (FEV1) measures how much air a person can exhale during the first second of a forced breath.
FEV1 = Race x 1.08 x [(0.0395 x Height) - (0.025 x Age) - 2.6]
Forced vital capacity (FVC) is the total amount of air exhaled during the FEV test.
FVC = Race x 1.15 x [(0.0443 x Height) - (0.026 x Age) - 2.89]
Where Race variables are: 0.93 for Asian, 0.87 for Black or African American and 1 for White Caucasian.
Interpretation
The normal value for the FEV1/FVC ratio is above 0.75. Values lower than 0.70 are suggestive of airflow limitation with an obstructive pattern whilst in restrictive lung diseases, this ratio is normal or high.
FEV1/FVC Ratios <70% are indicative of chronic obstructive pulmonary disease (COPD) or lower than 65% in patients older than 65 years.
Normal range FEV1 is between 3.0 and 5.0 L whilst normal range FEV1 is between 2.4 and 4.0 L. Lower FEV1 values are indicative of obstructive lung disease, such as asthma or COPD.
According to the European Respiratory Society (ERS) criteria, a FEV1% predicted of less than 88% (in men) and 89% (in women) defines when a patient has COPD. Where FEV1% predicted is defined as FEV1% of the patient divided by the average FEV1% in a similar gender, age and characteristics population.
References
Quanjer PhH, Tammeling GJ, Cotes JE, et al. Lung volume and forced ventilatory flows. Report Working Party Standardization of lung function tests. Official Statement European Respiratory Society. Eur Respir J. 1993; 6 Suppl 16: 5-40.
Falaschetti E, Laiho J, Primatesta P, Purdon S. Prediction equations for normal and low lung function from the Health Survey for England. Eur Respir J. 2004; 23(3):456-63.
Nathell L, Nathell M, Malmberg P, Larsson K. COPD diagnosis related to different guidelines and spirometry techniques. Respir Res. 2007; 8(1):89.
Specialty: Pulmonology
System: Respiratory
Article By: Denise Nedea
Published On: June 15, 2020 · 12:00 AM
Last Checked: June 15, 2020
Next Review: June 15, 2025