#1 Free Michaelis-Menten Equation Calculator (Enzyme Kinetics) 2025

Enzyme kinetics is the study of the rates of enzyme-catalyzed chemical reactions. The Michaelis-Menten model is one of the simplest and best-known models of enzyme kinetics.

Michaelis-Menten Equation:

V = (V_max * [S]) / (K_m + [S])

Where:

• V: Reaction velocity (or rate).
• V_max: Maximum reaction velocity, achieved when the enzyme is saturated with substrate.
• [S]: Substrate concentration.
• K_m: Michaelis constant. It is the substrate concentration at which the reaction velocity is half of V_max (V = V_max/2). K_m is an inverse measure of the affinity of the enzyme for its substrate; a lower K_m indicates higher affinity.

Significance:

• V_max reflects the catalytic efficiency of the enzyme under saturating substrate conditions.
• K_m provides insight into the enzyme-substrate interaction. It's a characteristic constant for a given enzyme and substrate pair under specific conditions (e.g., temperature, pH).

Lineweaver-Burk Plot (Double Reciprocal Plot):

This is a graphical representation of the Michaelis-Menten equation, obtained by taking the reciprocal of both sides:

1/V = (K_m / V_max) * (1/[S]) + 1/V_max

This equation is in the form y = mx + c, allowing for easier determination of V_max (from y-intercept) and K_m (from x-intercept or slope) from experimental data plotted as 1/V versus 1/[S].

1. Enter the Maximum Reaction Velocity (V_max). This value represents the rate of reaction when the enzyme is fully saturated with substrate. It must be a positive number.
2. Enter the Michaelis Constant (K_m). This is the substrate concentration at which the reaction rate is half of V_max. It must be a positive number.
3. Enter the Substrate Concentration ([S]). This is the concentration of the substrate available for the enzyme. It must be a non-negative number.
4. Click the "Calculate Velocity (V)" button.
5. The calculated Reaction Velocity (V) and a step-by-step solution will be displayed below.
6. An interactive graph will also be generated, visualizing the Michaelis-Menten curve with V_max, K_m, and the calculated point ([S], V) highlighted.
7. You can adjust the input values and recalculate to see how the reaction velocity and graph change.