About this calculator
This calculator uses the CKD-EPI 2021 equation, the current international standard, and also shows the older MDRD result and, if you add your weight, the Cockcroft-Gault creatinine clearance that doctors use for some medicine doses.
How to use it
- Enter the serum creatinine from your report and its unit.
- Enter your age and sex.
- Read the eGFR and its category.
The formula
- Scr
- serum creatinine in mg/dL
- κ
- 0.7 for women, 0.9 for men
- α
- −0.241 for women, −0.302 for men
Worked example
Creatinine 1.1 mg/dL, man aged 45
- Scr/κ = 1.1 ÷ 0.9 = 1.222.
- eGFR = 142 × 1.222^−1.2 × 0.993845 = 84 mL/min/1.73 m².
What the result means
90 or above is normal; 60 to 89 is usually fine without other signs of kidney damage; below 60 for more than three months indicates chronic kidney disease; below 15 is kidney failure.
eGFR falls slowly with age even in healthy people.
Assumptions
- Adults aged 18 and over with stable kidney function.
Limitations
- Less reliable with very high or low muscle mass, in pregnancy, in acute illness, after a heavy meat meal and with some medicines.
- Not for children.
Frequently asked questions
What is a normal eGFR?
90 or more. Values of 60 to 89 are common in older adults and are not kidney disease without other signs such as protein in the urine.
How do I convert creatinine from µmol/L to mg/dL?
Divide by 88.4.
Which equation do labs use?
Most now report CKD-EPI; some still print MDRD, which reads a little lower at normal kidney function.
What should I do if my eGFR is low?
Show the report to a doctor. A repeat test and a urine test are usually needed before any conclusion.
Not medical advice. This calculator is a general screening tool and cannot diagnose any condition. Results are estimates. Please talk to a doctor or a qualified health professional about your health and before making changes to diet, exercise or treatment.
Last reviewed on 7 October 2026. Found a mistake? Tell us.