Chemistry
Michaelis-Menten Equation Calculator
Predict the reaction velocity of an enzyme at any substrate concentration.
Your inputs
Change any value to update the result instantly.
Reaction velocity v
50 µmol/min
Percentage of V_max reached
50 %
Substrate needed for half V_max
5 mmol/L
Catalytic efficiency V_max/K_m
20
Reading
Working in the curved middle region of the plot
Michaelis-Menten assumes a steady state, no product inhibition and substrate in large excess over the enzyme. K_m equals the substrate concentration that gives half the maximum rate.
What this calculator does
Predicts enzyme reaction velocity at any substrate concentration from Vmax and Km.
What your result means
Velocity approaches Vmax as substrate rises; Km is the concentration giving half the maximum rate.
Velocity against substrate concentration
| Period | Input / invested | Calculated value |
|---|---|---|
| 0 | 100 | 0 |
| 2 | 100 | 28.5714 |
| 4 | 100 | 44.4444 |
| 6 | 100 | 54.5455 |
| 8 | 100 | 61.5385 |
| 10 | 100 | 66.6667 |
| 12 | 100 | 70.5882 |
| 14 | 100 | 73.6842 |
| 16 | 100 | 76.1905 |
| 18 | 100 | 78.2609 |
| 20 | 100 | 80 |
Formula and working
v = V_max[S] / (K_m + [S])
- 1
Collect the inputs
Maximum velocity V_max = 100 µmol/min; Michaelis constant K_m = 5 mmol/L; Substrate concentration [S] = 5 mmol/L
- 2
Apply the formula
v = V_max[S] / (K_m + [S])
- 3
Result
Reaction velocity v = 50 µmol/min
Frequently asked questions
Symbols and assumptions
- v
- Velocity
- V_max
- Maximum velocity
- K_m
- Michaelis constant
- [S]
- Substrate concentration
- • Steady-state conditions with substrate far in excess of enzyme.
- • No product inhibition or cooperativity.
Sources and review
Reviewed 2026-09-22 · Next review 2027-09-22
- • Allosteric and multi-substrate enzymes do not follow this single-substrate model.
Important limitation
This is an educational estimate based only on the values and formula shown. Verify current rates, rules, units, and professional standards before relying on the result. It is not personalized financial or investment advice.
Report a mistake or request an improvement
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