MDRD eGFR Calculator
Using the Modification of Diet in Renal Disease Study Equation
Last updated on: June 27, 2025
MDRD Calculator
What is the MDRD Equation?
The Modification of Diet in Renal Disease (MDRD) Study equation is a widely used formula to estimate the glomerular filtration rate (eGFR) from serum creatinine, age, sex, and race.
It is more accurate than the Cockcroft-Gault formula in many populations, especially in patients with chronic kidney disease, as it does not require a weight measurement.
Why is it Important?
- A cornerstone in the diagnosis, staging, and management of Chronic Kidney Disease (CKD).
- Helps healthcare providers make crucial decisions regarding medication dosing.
- More reliable for estimating GFR in elderly patients and those with varying body compositions.
Interpreting the Result (CKD Stages)
Stage 1: Normal or High GFR (≥ 90):
Kidney function is normal, but other evidence of kidney disease may be present.
Stage 2: Mildly Decreased GFR (60-89):
A mild reduction in kidney function. Lifestyle monitoring is advised.
Stage 3a: Mild-Moderate Decrease (45-59):
A moderate reduction in kidney function.
Stage 3b: Moderate-Severe Decrease (30-44):
A significant reduction in kidney function that requires medical management.
Stage 4: Severely Decreased GFR (15-29):
Severe kidney damage. Preparation for renal replacement therapy (dialysis) may be needed.
Stage 5: Kidney Failure (< 15):
End-stage renal disease, requiring dialysis or a kidney transplant.
Managing Kidney Health
An eGFR result should always be interpreted by a healthcare professional in the context of your overall health. General advice for kidney wellness includes:
- Controlling high blood pressure and diabetes.
- Adhering to a kidney-friendly diet (low in sodium, phosphorus, and protein as advised).
- Avoiding medications that can be harmful to the kidneys (nephrotoxic drugs).
- Regular follow-ups with your doctor to monitor kidney function.
This page has been medically reviewed by Dr. Khoulah Attia – PharmD, Immunology Specialist.