eGFR Calculator
Fast kidney function estimates using 17+ validated adult and pediatric equations.
Enter age, sex, and serum creatinine. Add cystatin C, height, or weight when available to unlock additional equations.
Patient data
Required: age, sex, and serum creatinine. Optional fields unlock more equations.
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Quick guide
This calculator compares validated kidney function equations and ranks the best fit first. It is built for fast clinical reference, not long-form reading.
Adult default
CKD-EPI 2021 is the preferred starting point for most adults.
Pediatric use
Children and young adults often need height-aware pediatric equations.
Extra biomarkers
Cystatin C, weight, and height enable additional validated equations.
CKD stage reference
FAQ
Which equation should I use?
For most adults, start with CKD-EPI 2021. For children, use pediatric equations such as Schwartz or CKiD. If cystatin C is available, combined equations can improve confidence.
What is a normal eGFR?
In adults, eGFR 90 mL/min/1.73 m2 or higher is typically considered normal. Lower values should be interpreted with albuminuria, trend over time, and clinical context.
Why are there multiple results?
Different equations are validated for different ages, biomarkers, and use cases. The calculator ranks the most appropriate option first and still lets you compare alternatives.
When do height and weight matter?
Weight is needed for Cockcroft-Gault. Height is often important for pediatric equations and for body surface area based conversions.
Can I rely on this alone for clinical decisions?
No. eGFR is an estimate. Use it alongside the patient history, medications, laboratory context, and clinical judgment.