. Author manuscript; available in PMC: 2015 Apr 15.

Published in final edited form as: N Engl J Med. 2012 Jul 5;367(1):20–29. doi: 10.1056/NEJMoa1114248

Table 2.

Creatinine Equation (CKD-EPI 2009), Cystatin C Equation (CKD-EPI 2012), and Creatinine–Cystatin C Equation (CKD-EPI 2012) for Estimating GFR, Expressed for Specified Sex, Serum Creatinine Level, and Serum Cystatin C Level.^*

Basis of Equation and Sex	Serum Creatinine^†	Serum Cystatin C	Equation for Estimating GFR
Basis of Equation and Sex	mg/dl	mg/liter	Equation for Estimating GFR
CKD-EPI creatinine equation^‡
Female	≤0.7		144 × (Scr/0.7)^−0.329 × 0.993^Age [× 1.159 if black]

Female	>0.7		144 × (Scr/0.7)^−1.209 × 0.993^Age [× 1.159 if black]

Male	≤0.9		141 × (Scr/0.9)^−0.411 × 0.993^Age [× 1.159 if black]

Male	>0.9		141 × (Scr/0.9)^−1.209 × 0.993^Age [× 1.159 if black]

CKD-EPI cystatin C equation^§
Female or male		≤0.8	133 × (Scys/0.8)^−0.499 × 0.996^Age [× 0.932 if female]

Female or male		>0.8	133 × (Scys/0.8)^−1.328 × 0.996^Age [× 0.932 if female]

CKD-EPI creatinine–cystatin C equation^¶

Female	≤0.7	≤0.8	130 × (Scr/0.7)^−0.248 × (Scys/0.8)^−0.375 × 0.995^Age [× 1.08 if black]
Female	≤0.7	>0.8	130 × (Scr/0.7)^−0.248 × (Scys/0.8)^−0.711 × 0.995^Age [× 1.08 if black]

Female	>0.7	≤0.8	130 × (Scr/0.7)^−0.601 × (Scys/0.8)^−0.375 × 0.995^Age [× 1.08 if black]
Female	>0.7	>0.8	130 × (Scr/0.7)^−0.601 × (Scys/0.8)^−0.711 × 0.995^Age [× 1.08 if black]

Male	≤0.9	≤0.8	135 × (Scr/0.9)^−0.207 × (Scys/0.8)^−0.375 × 0.995^Age [× 1.08 if black]
Male	≤0.9	>0.8	135 × (Scr/0.9)^−0.207 × (Scys/0.8)^−0.711 × 0.995^Age [× 1.08 if black]

Male	>0.9	≤0.8	135 × (Scr/0.9)^−0.601 × (Scys/0.8)^−0.375 × 0.995^Age [× 1.08 if black]
Male	>0.9	>0.8	135 × (Scr/0.9)^−0.601 × (Scys/0.8)^−0.711 × 0.995^Age [× 1.08 if black]

See Table S3 in the Supplementary Appendix for equations developed in the populations with chronic kidney disease.

^†

To convert the values for serum creatinine to micromoles per liter, multiply by 88.4.

^‡

The CKD-EPI creatinine equation (2009) that we developed previously³ can be expressed as a single equation: 141 × min(Scr/κ, 1)^α × max(Scr/κ, 1)^−1.209 × 0.993^Age [× 1.018 if female] [× 1.159 if black], where Scr is serum creatinine, κ is 0.7 for females and 0.9 for males, α is −0.329 for females and −0.411 for males, min is the minimum of Scr/κ or 1, and max is the maximum of Scr/κ or 1.

^§

The CKD-EPI cystatin C equation (2012) can be expressed as a single equation: 133 × min(Scys/0.8, 1)^−0.499 × max (Scys/0.8, 1)^−1.328 × 0.996^Age [× 0.932 if female], where Scys is serum cystatin C, min indicates the minimum of Scr/κ or 1, and max indicates the maximum of Scys/κ or 1.

^¶

The CKD-EPI creatinine–cystatin C equation (2012) can be expressed as a single equation: 135 × min(Scr/κ, 1)^α × max(Scr/κ, 1)^−0.601 × min(Scys/0.8, 1)^−0.375 × max(Scys/0.8, 1)^−0.711 × 0.995^Age [× 0.969 if female] [× 1.08 if black], where Scr is serum creatinine, Scys is serum cystatin C, κ is 0.7 for females and 0.9 for males, α is −0.248 for females and −0.207 for males, min indicates the minimum of Scr/κ or 1, and max indicates the maximum of Scr/κ or 1.