The initial rate, V₀, is the rate of the reaction after almost no time has passed, t is approximately 0. It is the measure of moles of product formed per second (t cannot equal zero, because we cannot divide by zero) and can be approximated by finding the slope of the product versus reactant curve at the beginning. Near beginning, the reverse reaction is negligible, and thus the slope is a good approximation.

File:Vo10.jpg

${\displaystyle V_{0}=k_{2}[ES]}$

${\displaystyle V_{0}={\frac {k_{cat}}{K_{M}}}[E][S]}$