# Glomerular Filtration Rate Calculator

This tool will helps you to measure kidney function based on recommended equation.

# Results

**Estimated GFR value (mL/min/1.73 m ^{2}) = 4751.25 mL/min/1.73 m^{2}**

# Results

**MDRD 4-Variable Equation = 18932.2 mL/min/1.73 m ^{2}**

**CKD-EPI Formula = 716 mL/min/1.73 m ^{2}**

**Mayo Quadratic Formula = 123 mL/min/1.73 m ^{2}**

## Glomerular filtration rate (GFR)

It is a test used to check how well the kidneys are working. importantly, it estimates how much blood passes through the glomeruli each minute.

Estimating glomerular filtration rate (GFR) from serum creatinine in children is the Bedside Schwartz equation.

**For Children :**

This formula is for people aged 18 years or younger.

GFR (mL/min/1.73 m^{2}) = (36.2 × Height in cm) / Creatinine in μmol/L< (SI Units)/p>

GFR (mL/min/1.73 m^{2}) = (0.41 × Height in cm) / Creatinine in mg/dL (conventional units)

**MDRD for Adults :**

GFR (mL/min/1.73 m^{2}) = 175 × (S_{cr}/88.4)^{-1.154} × (Age)^{-0.203} × (0.742 if female) × (1.212 if African American) (SI units)

GFR (mL/min/1.73 m^{2}) = 175 × (S_{cr})^{-1.154} × (Age)^{-0.203} × (0.742 if female) × (1.212 if African American) (conventional units)

**CKD-EPI Adults :**

GFR = 141 × min(S_{cr}/k, 1)^{α} × max(S_{cr}/k, 1)^{-1.209} × 0.993^{Age} × 1.018 [if female] × 1.159 [if African American] (SI Units)

Where,

S_{cr} is serum creatinine in μmol/L,

α is 61.9 for females and 79.6 for males,

a is -0.329 for females and -0.411 for males,

min indicates the minimum of S_{cr}/k or 1, and

max indicates the maximum of S_{cr}/k or 1

GFR = 141 × min(S_{cr}/k, 1)^{α} × max(S_{cr}/k, 1)^{-1.209} × 0.993^{Age} × 1.018 [if female] × 1.159 [if African American] (conventional units)

Where,

S_{cr} is serum creatinine in mg/dL,

α is 0.7 for females and 0.9 for males,

a is -0.329 for females and -0.411 for males,

min indicates the minimum of S_{cr}/k or 1,

max indicates the maximum of S_{cr}/k or 1

**Mayo Quadratic Formula**

If S_{Cr} < 0.8 mg/dL, use 0.8 mg/dL for S_{Cr}

GFR = e^{(1.911 + 5.249/SCr - 2.114/SCr2 - 0.00686 × age - (0.205 if female))}

Where,

e = 2.71828182845905

#### Convert μmol/l and mg/dl :

μmol/l is the most common measurement used in the UK with mg/dL predominantly used in the united states.

To convert μmol/l to mg/dl, multiply by 0.0113. To convert mg/dl to μmol/l, multiply by 88.4.

**Chronic Kidney Disease Stages**

Stage | GFR Value (mL/min/1.73 m^{2}) |
---|---|

Normal | 90+ or above and no proteinuria |

CKD1 | 90+ with evidence of kidney damage |

CKD2 (Mild) | 60 to 89 with evidence of kidney damage |

CKD3 (Moderate) | 30 to 59 |

CKD4 (Severe) | 15 to 29 |

CKD5 Kidney failure | less than 15 |

**Population Mean Estimated GFR**

Age | Mean Estimated GFR (mL/min/1.73 m ^{2}) |
---|---|

20-29 | 116 |

30-39 | 107 |

40-49 | 99 |

50-59 | 93 |

60-69 | 85 |

70+ | 75 |

**References**

Schwartz GJ, et al. New equations to estimate GFR in children with CKD. J Am Soc Nephrol. 2009;20:629-637.

Schwartz GJ and Work DF. Measurement and estimation of GFR in children and adolescents. Clin J Am Soc Nephrol. 2009;4(11):1832-43.

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.