GFR Calculator
Calculate estimated Glomerular Filtration Rate (eGFR) using the CKD-EPI formula.
Patient Information
Normal range: 0.6-1.2 mg/dL (men), 0.5-1.1 mg/dL (women)
Note: Some organizations are moving away from race-based adjustments
eGFR Result
Estimated GFR
87.4
mL/min/1.73m²
CKD Stage
Stage 2
Mildly Decreased
Reference Ranges:
Normal: ≥90
Stage 2: 60-89
Stage 3a: 45-59
Stage 3b: 30-44
Stage 4: 15-29
Stage 5: <15
⚠️ Medical Disclaimer:
This calculator is for educational purposes only. Always consult with a healthcare provider for interpretation of results and medical advice.
About This Calculator
The GFR (Glomerular Filtration Rate) Calculator estimates your kidney function using the CKD-EPI (Chronic Kidney Disease Epidemiology Collaboration) formula. eGFR measures how well your kidneys filter waste from your blood and is a key indicator of kidney health.
This calculator uses serum creatinine levels, age, gender, and race to estimate GFR. Normal eGFR is typically 90 or above. Lower values indicate reduced kidney function. This is a screening tool and should not replace professional medical evaluation.
Formula & Calculation Method
CKD-EPI Formula for eGFR:
eGFR = 141 × min(Scr/κ, 1)^α × max(Scr/κ, 1)^-1.209 × 0.993^Age × [1.018 if female] × [1.159 if black]
where:
Scr = Serum Creatinine (mg/dL)
κ = 0.7 (female) or 0.9 (male)
α = -0.329 (female) or -0.411 (male)
The CKD-EPI formula is the current standard for estimating GFR and is more accurate than older formulas like MDRD, especially at higher GFR levels. The formula accounts for age, gender, and race differences in creatinine production and muscle mass.
How to Use This Calculator
- Enter Age: Input your age in years (18+).
- Select Gender: Choose your biological sex.
- Enter Creatinine: Input your serum creatinine level in mg/dL (from blood test).
- Select Race: Choose your race (affects calculation).
- View Results: See your estimated GFR and CKD stage.
Note: This calculator requires a recent blood test result for serum creatinine. Consult with a healthcare provider for interpretation of results.
Frequently Asked Questions
What is a normal eGFR?
Normal eGFR is typically 90 mL/min/1.73m² or higher. Values between 60-89 may indicate mild kidney disease, while values below 60 indicate chronic kidney disease. However, eGFR naturally decreases with age.
What do the CKD stages mean?
Stage 1: Normal or high (≥90), Stage 2: Mildly decreased (60-89), Stage 3a: Mildly to moderately decreased (45-59), Stage 3b: Moderately to severely decreased (30-44), Stage 4: Severely decreased (15-29), Stage 5: Kidney failure (<15).
Why does race affect the calculation?
Research shows that people of African descent tend to have higher muscle mass and creatinine production, which affects the formula. However, this is a controversial aspect of the formula, and some medical organizations are moving away from race-based adjustments.
Can I use this instead of seeing a doctor?
No. This calculator is for educational purposes only. eGFR should be interpreted by a healthcare professional in the context of your overall health, medical history, and other test results. Always consult with a doctor for medical advice.
NumCalculators Editorial Team
Multi-disciplinary Expert Team
The NumCalculators Editorial Team consists of subject matter experts across various fields who review and verify the accuracy of our calculators. Each calculator undergoes rigorous testing and validation before publication.