eGFR = 142 × min(Scr/κ, 1)^α × max(Scr/κ, 1)^−1.200 × 0.9938^age × 1.012 if female; κ = 0.7 (female) or 0.9 (male), α = −0.241 (female) or −0.302 (male).
What your result means
eGFR is reported in mL/min/1.73m² and falls gradually with age in healthy adults, so the same number means different things at 30 and at 75.
A single low result is usually repeated, because creatinine moves with hydration, muscle mass and recent exercise, and kidney function is judged on results over time together with urine tests.
Your own lab's printed range and your clinician's read of your history come first; this calculator is educational and is not a diagnosis.
The CKD-EPI 2021 creatinine equation, which removed the race coefficient used in older versions.
Why does eGFR go down with age?
Filtration declines gradually across adulthood, which is why population ranges are lower in older age groups.
Can muscle mass change my eGFR?
Yes. Creatinine comes from muscle, so very muscular people can show a lower eGFR and people with little muscle a higher one than their true filtration.