# CKD-EPI Calculator for Adults (SI Units)

In adults, the most widely-used equations for estimating glomerular filtration rate (GFR) from serum creatinine are the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation1 and the isotope dilution mass spectrometry (IDMS) traceable Modification of Diet in Renal Disease (MDRD) Study equation2. NKDEP’s calculators rely on creatinine determinations which are isotope dilution mass spectrometry (IDMS) traceable. All laboratories should be using creatinine methods calibrated to be IDMS traceable. Read more about reporting GFR and creatinine standardization.

This CKD-EPI equation calculator should be used when Scr is reported in µmol/L. This equation is recommended when eGFR values above 60 mL/min/1.73 m² are desired.

GFR = 141 × min(Scr/κ, 1)α × max(Scr/κ, 1)-1.209 × 0.993Age × 1.018 [if female] × 1.159 [if black]

where:
Scr is serum creatinine in µmol/L,
κ is 61.9 for females and 79.6 for males,
α is -0.329 for females and -0.411 for males,
min indicates the minimum of Scr/κ or 1, and
max indicates the maximum of Scr/κ or 1

The equation does not require weight because the results are reported normalized to 1.73 m² body surface area, which is an accepted average adult surface area.

Enter a numeric value of at least 0.001
Enter a numeric age, 18 or over
African American?
Gender
GFR value (mL/min/1.73 m²**)
mL/min/1.73 m²

*This equation should only be used for patients 18 and older.

**The NKDEP presently recommends reporting estimated GFR values greater than or equal to 60 mL/min/1.73 m² simply as “≥ 60 mL/min/1.73 m²,” not an exact number.

## References

1. Levey AS, Stevens LA, Schmid CH, Zhang YL, Castro AF, 3rd, Feldman HI, et al. A new equation to estimate glomerular filtration rate. Ann Intern Med. 2009;150(9):604-12.

2. Levey AS, Coresh J, Greene T, Stevens LA, Zhang YL, Hendriksen S, Kusek JW, Van Lente F; Chronic Kidney Disease Epidemiology Collaboration. Using standardized serum creatinine values in the modification of diet in renal disease study equation for estimating glomerular filtration rate. Ann Intern Med. 2006 Aug 15;145(4):247-54.