CKD-EPI 2021 Race-Free eGFR

Estimates glomerular filtration rate (GFR) using the 2021 CKD-EPI creatinine equation, which is race-free and recommended by NIDDK and KDIGO for adults ages 18 and older.

mg/dL
IDMS-traceable serum creatinine in mg/dL. If umol/L, divide by 88.4.
years
Age in years. Equation validated for adults >= 18.
Female uses kappa=0.7, alpha=-0.241, and female factor=1.012. Male uses kappa=0.9, alpha=-0.302.

References

  1. eGFR Equations for Adults - NIDDK — National Institute of Diabetes and Digestive and Kidney Diseases (2025)
  2. New Creatinine- and Cystatin C-Based Equations to Estimate GFR without Race — New England Journal of Medicine (2021)

Note: Combined creatinine-cystatin C equation is more accurate and preferred when available. CKD-EPI 2021 replaced the race-based 2009 CKD-EPI equation.

Warnings & Limitations

  • eGFR may overestimate in non-Black individuals by ~4% and underestimate in Black individuals by ~4% compared to combined creatinine-cystatin C equation.
  • Less accurate in acute kidney injury, pregnancy, amputees, extremes of muscle mass.
  • For drug dosing decisions near critical thresholds, consider using combined creatinine-cystatin C equation or measured GFR.
  • Equation not validated for children <18 years.