GFR Calculator
This calculator estimates your Glomerular Filtration Rate (GFR), the standard measure of how well your kidneys are filtering waste and excess fluid from your blood, using the four-variable MDRD (Modification of Diet in Renal Disease) formula. You enter your gender, ethnicity (black or non-black, since muscle mass and creatinine production differ between groups), your age in years, and your plasma creatinine level in umol/L, which you get from a blood test. The calculator returns your estimated GFR in mL/min/1.73m2 and matches it against the five stages of chronic kidney disease, from normal renal function (Stage 1, GFR of 90 or above) through to very severe renal failure (Stage 5, GFR below 15), along with the general management approach for that stage. Below the results you will find a full staging table plus population mean eGFR figures by age band, so you can see how your result compares with others your age. Because creatinine based formulas are sensitive to muscle mass, diet, hydration, pregnancy and the laboratory method used, treat the result as a screening guide rather than a diagnosis, and expect some variation from the figure your GP or lab reports. This tool is for general information and education only, not medical advice; do not change any treatment based on it, and discuss your kidney function and any results with your doctor.
STAGES OF CHRONIC KIDNEY DISEASE AND MANAGEMENT:
| Stage: | GFR Rate: | Description: | Management: |
| 1 | 90 + | Normal renal function | Observation and control of blood pressure |
| 2 | 60-89 | Mildly reduced renal function | Observation, control of blood pressure and cardiovascular risk factors. |
| 3 | 45-59 | Moderate decrease in renal function | Observation, control of blood pressure and cardiovascular risk factors. |
| 3b. | 30-44 | Moderate decrease in renal function | Observation, control of blood pressure and cardiovascular risk factors. |
| 4 | 15-29 | Severely reduced renal function. | Planning for renal failure. |
| 5 | <15 | Very severe renal failure | Transplant or dialysis |
POPULATION MEAN ESTIMATED GLOMERULAR FILTRATION RATES:
| Age in Years: | Mean eGFR |
| 20-29 | 116 mL/min/1.73 m2 |
| 30-39 | 107 mL/min/1.73 m2 |
| 40-49 | 99 mL/min/1.73 m2 |
| 50-59 | 93 mL/min/1.73 m2 |
| 60-69 | 85 mL/min/1.73 m2 |
| 70+ | 75 mL/min/1.73 m2 |
*This GFR Calculator is for educational uses only and should not be used in an emergency or for the treatment of medical conditions. If you feel that you have concerns over your health please consult your doctor.