What this calculator does
Michaelis–Menten kinetics works out enzyme reaction rate at a given substrate concentration. Enter your own figures above and the answer updates as you type: nothing is fixed in the code, so the result reflects exactly the numbers you supply.
The formula this calculator evaluates is printed under the tool and explained below, so you can check the working by hand or reuse it in a spreadsheet.
The formula
Formulav = Vmax[S] / (Km + [S])
The inputs explained
| Field | What to enter |
|---|---|
| Vmax (µmol/min) | A number, measured in µmol/min. Starts at 100. |
| Km (mM) | A number, measured in mM. Starts at 10. |
| Substrate concentration [S] (mM) | A number, measured in mM. Starts at 5. |
Worked examples
Every figure in the tables below is produced by this page’s own calculator at build time, so the numbers and the tool always agree. Select any row to load that scenario.
How the answer changes with vmax
Every other input is held at the calculator’s starting values while vmax varies. Select any row to load that scenario into the calculator.