TFG MDRD 4 var
- Created by
- Renato Passos, Eng. de Software
- Reviewed by
- Renato Passos, Eng. de Software
Last updated: Apr 18, 2026
About this calculator
The TFG MDRD 4 Var calculator estimates glomerular filtration rate (GFR), a key indicator of kidney function. It uses the formula 186 × (Creatinine)^-1.154 × (Age)^-0.203, adjusted for sex and race. This formula is widely adopted in adults for clinical assessments and research to evaluate kidney health.
The formula incorporates serum creatinine levels, a muscle metabolism byproduct, and the patient's age. Results below 60 ml/min/1.73m² suggest reduced kidney function. However, this calculator is not suitable for children, pregnant individuals, or those with malnutrition, as it may underestimate GFR in these groups.
To use correctly, input serum creatinine and age into the calculator. Results should be interpreted by a nephrologist alongside other tests, such as urinalysis and imaging. Abnormal values may indicate kidney disease, requiring medical follow-up and medication adjustments.
Frequently asked questions
What is the MDRD 4-variable formula?
It estimates GFR (Glomerular Filtration Rate) using serum creatinine, age, sex, and race. More accurate than older formulas, it's recommended for adults without malnutrition.
Who should use this calculator?
Adults with suspected kidney disease, diabetes, or hypertension, and healthcare professionals evaluating renal function in non-pregnant adults.
Why might results be inaccurate?
The formula assumes average muscle mass. It may underestimate GFR in elderly, women, or individuals with low muscle mass.
How to interpret GFR values?
Over 90 ml/min/1.73m² is normal. 60-89 indicates mild reduction. Below 60 suggests chronic kidney disease, depending on clinical context.