Estimated GFR Calculator
Kidney health is essential for overall well-being, yet many people are unaware of how well their kidneys are functioning. One of the most important indicators of kidney function is the glomerular filtration rate (GFR). The Estimated GFR (eGFR) Calculator allows you to quickly assess your kidney function using accurate formulas and understand your risk for chronic kidney disease (CKD).
Whether you are a patient, caregiver, or healthcare professional, this calculator provides reliable eGFR results, CKD stage classification, and a simple interpretation of your kidney function.
What Is eGFR?
The glomerular filtration rate (GFR) measures how well your kidneys filter blood. A normal GFR indicates that your kidneys are efficiently removing waste from your body, while a reduced GFR can signal kidney damage or disease.
Estimated GFR (eGFR) is calculated using formulas that consider:
- Serum creatinine levels – A waste product in your blood.
- Age – Kidney function typically declines with age.
- Gender – Differences in muscle mass affect creatinine levels.
- Race – Some formulas adjust for race due to population differences in creatinine levels.
- Weight – Used in the Cockcroft-Gault formula.
How the eGFR Calculator Works
Our calculator supports three widely used eGFR formulas:
- CKD-EPI (2021) – The most accurate for general populations and recommended for clinical practice.
- MDRD (Modification of Diet in Renal Disease) – Useful for patients with chronic kidney disease.
- Cockcroft-Gault – Estimates creatinine clearance using age, weight, and gender, often used for drug dosing.
You simply enter your age, gender, race, serum creatinine, and weight (if using Cockcroft-Gault). The calculator then provides:
- eGFR value (mL/min/1.73m²)
- CKD stage (Stages 1–5)
- Kidney function description
- Interpretation of your results
How to Use the eGFR Calculator
- Select Calculation Method
Choose CKD-EPI, MDRD, or Cockcroft-Gault. Selecting Cockcroft-Gault will prompt you to enter your weight. - Enter Your Age
Input your age in years (18–120). Kidney function naturally declines with age. - Choose Gender and Race
Gender and race are important factors for accurate eGFR calculation. - Enter Serum Creatinine
Your serum creatinine in mg/dL is required for the calculation. - Enter Weight (if needed)
Cockcroft-Gault uses weight in kilograms to estimate creatinine clearance. - Click “Calculate”
The calculator instantly provides your eGFR, CKD stage, kidney function, and a simple interpretation. - Reset for New Calculations
Use the “Reset” button to enter different data for comparison or monitoring over time.
Example: eGFR Calculation
Let’s say a 55-year-old female has:
- Serum Creatinine: 1.1 mg/dL
- Weight: 65 kg
- Race: Other
Using CKD-EPI (2021):
- eGFR = 68.3 mL/min/1.73m²
- CKD Stage: Stage 2 (G2)
- Kidney Function: Mild Reduction
- Interpretation: Mildly reduced kidney function
Using Cockcroft-Gault:
- eGFR = 57.7 mL/min
- Interpretation: Mild to moderate reduction
This allows patients and clinicians to track kidney function trends accurately.
CKD Stages Based on eGFR
Understanding CKD stages helps identify the severity of kidney disease:
| Stage | eGFR (mL/min/1.73m²) | Kidney Function | Interpretation |
|---|---|---|---|
| 1 (G1) | ≥90 | Normal or High | Normal kidney function |
| 2 (G2) | 60–89 | Mild Reduction | Mildly reduced kidney function |
| 3a (G3a) | 45–59 | Mild to Moderate | Mild to moderately reduced |
| 3b (G3b) | 30–44 | Moderate to Severe | Moderately to severely reduced |
| 4 (G4) | 15–29 | Severe Reduction | Severely reduced kidney function |
| 5 (G5) | <15 | Kidney Failure | Kidney failure – dialysis may be needed |
Benefits of Using the eGFR Calculator
- Quick Kidney Function Assessment – Instant eGFR results without manual calculations.
- Multiple Formulas – CKD-EPI, MDRD, and Cockcroft-Gault for different clinical scenarios.
- Track CKD Progression – Monitor kidney function over time.
- Patient-Friendly – Clear interpretation and CKD stage for easier understanding.
- Clinical Reference – Helps healthcare providers estimate dosing for kidney-sensitive medications.
Tips for Accurate Results
- Use recent serum creatinine values from lab tests.
- Enter your exact age, weight, and gender.
- Select the formula recommended by your healthcare provider.
- Interpret results in conjunction with other clinical information.
- Regularly monitor kidney function if you have risk factors such as diabetes or hypertension.
Frequently Asked Questions (FAQs)
- What is eGFR?
eGFR is an estimate of how well your kidneys filter blood. - Why are there different formulas?
CKD-EPI, MDRD, and Cockcroft-Gault account for different variables and populations. - What is considered normal eGFR?
90 mL/min/1.73m² or higher is considered normal kidney function. - What does Stage 3 CKD mean?
Stage 3 indicates moderate reduction in kidney function (eGFR 30–59). - Can eGFR change over time?
Yes, kidney function can decline or improve based on health, medications, or interventions. - Do I need to fast before testing?
No fasting is needed, but eGFR is calculated from your blood test results. - Is race necessary for calculation?
Some formulas adjust for race to improve accuracy, particularly CKD-EPI and MDRD. - Can children use this calculator?
This version is designed for adults (age 18+). Pediatric calculations use different equations. - Does weight affect eGFR?
Only Cockcroft-Gault uses weight; CKD-EPI and MDRD do not. - Can medications affect eGFR?
Yes, certain medications can temporarily alter kidney function. - How often should I check eGFR?
At least once a year for healthy adults; more frequently if you have risk factors. - Is eGFR the same as creatinine clearance?
Not exactly; creatinine clearance is another measure of kidney function. - Can dehydration affect results?
Yes, dehydration can temporarily reduce eGFR. - Should I consult a doctor?
Always discuss abnormal eGFR results with your healthcare provider. - Can I monitor CKD progression?
Regular eGFR testing helps track kidney health over time.
Conclusion
The Estimated GFR Calculator is an essential tool for monitoring kidney health. By providing eGFR, CKD stage, and interpretation based on reliable formulas, it helps patients and healthcare providers make informed decisions about treatment, lifestyle, and risk management.
Regular monitoring of kidney function can help prevent complications, detect early disease, and guide interventions. Use this calculator as part of your routine health check-ups to take control of your kidney health today.