Renal clearance ratio

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


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


 * X is the analyte substance
 * Cx is the renal plasma clearance of X
 * Cin is the renal plasma clearance of inulin.

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