MDRD eGFR Calculator
Estimate kidney function using the 4-variable MDRD equation. Result is reported as mL/min/1.73 m².
If using µmol/L, value will be converted automatically.
Many institutions now avoid race-based adjustments. Use according to your local clinical policy.
What this MDRD calculator does
This tool estimates eGFR (estimated glomerular filtration rate) using the classic 4-variable MDRD Study equation: serum creatinine, age, sex, and an optional historical race coefficient. eGFR is a widely used marker for kidney function and helps clinicians stage chronic kidney disease (CKD).
While MDRD is still common in older workflows, many labs now report CKD-EPI equations because they tend to perform better at higher GFR ranges. Still, MDRD remains important for historical comparison and understanding legacy clinical records.
MDRD formula used in this page
The calculator uses the 4-variable IDMS-traceable MDRD equation:
eGFR = 175 × (Scr)-1.154 × (Age)-0.203 × (0.742 if female) × (1.212 if race coefficient is applied)
- Scr = serum creatinine in mg/dL
- If creatinine is entered in µmol/L, it is converted to mg/dL by dividing by 88.4
- Result is normalized to body surface area of 1.73 m²
How to interpret your eGFR result
eGFR values are grouped into CKD G-stages. Interpretation should always include urine albumin, trend over time, medications, blood pressure, and overall clinical context.
| Stage | eGFR (mL/min/1.73 m²) | General Meaning |
|---|---|---|
| G1 | ≥ 90 | Normal or high (CKD only if other kidney damage markers exist) |
| G2 | 60–89 | Mildly decreased (context matters) |
| G3a | 45–59 | Mild to moderate decrease |
| G3b | 30–44 | Moderate to severe decrease |
| G4 | 15–29 | Severely decreased |
| G5 | < 15 | Kidney failure range |
Important limitations of MDRD
1) Less accurate at higher kidney function
MDRD tends to underestimate measured GFR when kidney function is near normal. That is one reason many centers moved to CKD-EPI.
2) Creatinine can be influenced by muscle mass
Creatinine is not a perfect filtration marker. Very muscular patients, low muscle mass states, amputees, and some diet patterns can shift creatinine independently of true filtration.
3) Not for acute kidney injury (AKI) diagnosis
eGFR equations assume steady-state creatinine. In rapidly changing kidney function, equation-based estimates may be misleading.
When to discuss results with a clinician
- eGFR below 60 for 3 months or longer
- Rapid decline in eGFR over serial labs
- Proteinuria/albuminuria, hematuria, or resistant hypertension
- Diabetes, heart disease, or family history of kidney disease
- Medication review needs (NSAIDs, contrast exposure, dose adjustments)
MDRD vs CKD-EPI in plain language
Both equations estimate kidney function from blood creatinine and demographics. CKD-EPI generally gives better performance across broader GFR ranges and is preferred in many modern guidelines and labs. MDRD remains useful where historical continuity matters, including old datasets and previously established care pathways.
Bottom line
Use this MDRD calculator for educational and informational purposes, trend tracking, and legacy comparison. For diagnosis, medication decisions, and CKD management, interpret eGFR alongside urine albumin, blood pressure, symptoms, and clinician judgment.