Definitions

# Renal clearance ratio

The renal clearance ratio or fractional excretion is a measure of the speed at which a constituent of urine passes through the kidneys. It is defined by following equation:

$clearance ratio of X = frac\left\{C_x\right\}\left\{C_\left\{in\right\}\right\}$

Creatinine is sometimes used instead of inulin as the reference substance.