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Calcimator

Enzyme Kinetics (Michaelis-Menten)

Calculate reaction velocity from Vmax, Km, and substrate concentration using the Michaelis-Menten equation.

Inputs

Results

Reaction Velocity (v)

71.4286

% of Vmax

71.43%

Enzyme Saturation71.43%
Vmax/Km (Efficiency)10
1/v (Lineweaver-Burk)0.014
1/[S] (Lineweaver-Burk)0.04
How to Use This Calculator
  1. Enter Vmax (max velocity), Km (Michaelis constant), and Substrate Concentration [S].
  2. Review Reaction Velocity (v) and % of Vmax.
  3. Use Enzyme Saturation (%) and Vmax/Km (Efficiency) to inform your decision.
  4. Use the chart to visualize the results and explore different scenarios by adjusting inputs.

How the result changes with Vmax (max velocity)

Vmax (max velocity)Reaction Velocity (v)% of Vmax
10,0007,142.857171.43%
35,00025,00071.43%
65,00046,428.571471.43%
90,00064,285.714371.43%

What each input means

Vmax (max velocity)
Maximum reaction velocity when enzyme is fully saturated. Units depend on your assay (e.g., μmol/min).
Km (Michaelis constant)
Substrate concentration at half-maximal velocity. Lower Km means higher enzyme affinity.
Substrate Concentration [S]
Current substrate concentration in the same units as Km.

How this is calculated

Formula

v = Vmax × [S] / (Km + [S])

Worked example, using the default values

  1. Identify Input Parameters
    Vmax (max velocity) = 100, Km (Michaelis constant) = 10, Substrate Concentration [S] = 25 = 3 input(s) provided
  2. Calculate Reaction Velocity
    Reaction Velocity
    71.4286 = 71.4286
  3. Calculate % of Vmax
    % of Vmax
    71.43 = 71.43
  4. Calculate Enzyme Saturation
    Enzyme Saturation
    71.43 = 71.43
  5. Calculate Vmax/Km
    Vmax/Km
    10 = 10

Engine last updated . Checked against 2 independently-derived tests — how we verify calculators.

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