ganak.appeGFR Calculator
Free eGFR calculator to estimate your kidney function using the CKD-EPI 2021, CKD-EPI 2009, MDRD, and Cockcroft-Gault equations. Enter serum creatinine, age, and sex for instant results with CKD staging (KDIGO G1–G5), risk classification, and all-equation comparison. Supports mg/dL and µmol/L creatinine units.
Recommended by NKF/ASN. Race-free equation published in 2021.
estimated GFR
CKD Stage
G1
Risk Level
Low Risk
Equation
CKD-EPI 2021
Compare All Equations
Side-by-side eGFR results from all supported equations
CKD Stage G1: Normal or High
Kidney function is normal. Monitor if other risk factors are present (e.g. diabetes, hypertension).
CKD-EPI 2021Selected
Stage G1 — Normal or High
94.6
mL/min/1.73 m²
CKD-EPI 2009
Stage G1 — Normal or High
90.5
mL/min/1.73 m²
MDRD
Stage G2 — Mildly Decreased
80.8
mL/min/1.73 m²
Cockcroft-Gault
Stage G1 — Normal or High
92.4
mL/min
Cockcroft-Gault uses default weight of 70 kg. Select it as the equation to adjust weight.
This calculator provides estimates for educational purposes only. It is not a substitute for professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider for interpretation of your results.
What is eGFR?
Understanding estimated glomerular filtration rate
eGFR (estimated Glomerular Filtration Rate) measures how well your kidneys filter waste from your blood. It is the best overall indicator of kidney function and is used to diagnose and stage chronic kidney disease (CKD).
A normal eGFR is 90 mL/min/1.73 m² or higher. Values below 60 sustained for 3 or more months indicate chronic kidney disease. eGFR is estimated from a blood test (serum creatinine) along with age and sex.
eGFR Formulas
Equations used to estimate kidney function
This calculator supports four clinically validated equations. The CKD-EPI 2021 equation is recommended by the National Kidney Foundation (NKF) and American Society of Nephrology (ASN).
CKD-EPI 2021 (Recommended)
Where κ = 0.7 (female) or 0.9 (male), α = -0.241 (female) or -0.302 (male), S = 1.012 (female) or 1 (male).
MDRD
Cockcroft-Gault
Note: Estimates creatinine clearance (mL/min), not eGFR. Used primarily for drug dosing.
CKD Stages by eGFR
KDIGO classification of chronic kidney disease
The Kidney Disease: Improving Global Outcomes (KDIGO) guidelines classify CKD into stages based on eGFR. Diagnosis requires abnormalities persisting for more than 3 months.
| Stage | eGFR | Description |
|---|---|---|
| G1 | ≥ 90 | Normal or high |
| G2 | 60–89 | Mildly decreased |
| G3a | 45–59 | Mildly to moderately decreased |
| G3b | 30–44 | Moderately to severely decreased |
| G4 | 15–29 | Severely decreased |
| G5 | < 15 | Kidney failure |
What Affects eGFR?
Factors that influence your kidney function estimate
Several factors can influence your eGFR result beyond actual kidney function:
- High-protein diets or creatine supplements can temporarily raise creatinine, lowering eGFR
- Very muscular individuals may have higher creatinine that does not reflect kidney damage
- Dehydration can temporarily lower eGFR
- Certain medications (e.g. trimethoprim, cimetidine) can raise creatinine without affecting kidney function
- eGFR equations are less accurate at values above 90; labs often report "> 90" rather than an exact number
Serum Creatinine
About the blood test used to estimate eGFR
Serum creatinine is a waste product from normal muscle metabolism. Healthy kidneys filter creatinine from the blood. When kidney function declines, creatinine levels rise.
Normal serum creatinine ranges are approximately 0.7–1.3 mg/dL (62–115 µmol/L) for adult males and 0.6–1.1 mg/dL (53–97 µmol/L) for adult females. Your lab may use slightly different reference ranges.
Frequently Asked Questions
Common questions about eGFR and kidney function