GFR Calculator
Calculate estimated Glomerular Filtration Rate for kidney function assessment
Calculate eGFR
Valid for adults 18+ years
Normal: 0.7-1.3 mg/dL (62-115 μmol/L)
CKD Stages by eGFR
Which Method to Use?
Creatinine Only
Standard method, widely available test
Cystatin C Only
Better for patients with unusual muscle mass
Both Combined
Most accurate, recommended when both available
Normal Lab Values
Serum Creatinine
Male: 0.9-1.3 mg/dL
Female: 0.7-1.1 mg/dL
Serum Cystatin C
Adult: 0.5-1.2 mg/L
Normal eGFR
Adults: 90-120 mL/min/1.73m²
Important Notes
Understanding eGFR (Estimated Glomerular Filtration Rate)
What is eGFR?
eGFR measures how well your kidneys filter blood. It estimates the volume of blood filtered by the glomeruli (tiny kidney filters) per minute, standardized to 1.73 m² body surface area. This standardization allows comparison between people of different sizes.
Why is eGFR Important?
- •Early detection of kidney disease
- •Monitoring progression of chronic kidney disease
- •Guiding treatment decisions
- •Determining need for specialist referral
Calculation Methods
CKD-EPI (2009)
Most widely used, based on creatinine
CKD-EPI Cystatin C
Independent of muscle mass
CKD-EPI Combined
Uses both markers, most accurate
MDRD
Alternative method, less accurate
Factors Increasing Creatinine
- • High muscle mass
- • High protein diet
- • Creatine supplements
- • Certain medications
- • Dehydration
Factors Decreasing Creatinine
- • Low muscle mass
- • Advanced age
- • Vegetarian diet
- • Malnutrition
- • Pregnancy
Advantages of Cystatin C
- • Not affected by muscle mass
- • More stable production
- • Better in elderly patients
- • Useful in special populations
⚠️ Important Medical Disclaimer
This calculator is for educational purposes only and should not replace professional medical advice.
- • Always consult with a qualified physician for kidney function evaluation
- • eGFR should be interpreted within the full clinical context
- • Consider other kidney function tests and clinical findings
- • Regular monitoring may be needed for chronic kidney disease
- • Different laboratories may have slightly different reference ranges