VEF1 Previsto (Knudson)
- Created by
- Renato Passos, Eng. de Software
- Reviewed by
- Renato Passos, Eng. de Software
Last updated: Apr 18, 2026
Formula
VEF1 pred
About this calculator
The VEF1 Predicted (Knudson) calculator is a useful tool for doctors and patients who want to estimate the forced pulmonary capacity of the patient (VEF1) based on height and age.
This formula was proposed by Knudson in 1983 and is widely used in pulmonology to evaluate the pulmonary function in patients with respiratory diseases.
To get accurate results, it's essential to keep in mind that this is an estimate and not a direct calculation of the forced pulmonary capacity. Additionally, age and height are important factors to consider for VEF1 estimation, and the formula may not be perfect for all cases.
Still, this calculator can be a useful tool for healthcare professionals to get a quick idea of the patient's forced pulmonary capacity and to discuss the results with the patient.
Frequently asked questions
What factors are considered in the Knudson formula?
The Knudson formula considers the patient's height and age to estimate the forced pulmonary capacity (VEF1).
Why is the Knudson formula not perfect for all cases?
This occurs because age and height are important factors for VEF1 estimation and because the formula may not be perfect for all cases.
What is the forced pulmonary capacity (VEF1)?
The forced pulmonary capacity (VEF1) is the amount of air a patient can exhale forcefully in one second.
When should I use this calculator?
This calculator can be used to get a quick idea of the patient's forced pulmonary capacity and to discuss the results with the patient.
What are the important precautions when using this calculator?
It's essential to keep in mind that this is an estimate and not a direct calculation of the forced pulmonary capacity, and also to consider that age and height are important factors for VEF1 estimation.