Chemistry / CALCULATOR

Arrhenius Rate Constant

Arrhenius Rate Constant: explore an explicit model with input checks, a formula and a worked example.

Runs on your deviceUpdates as you typeFormula & example ↓
01

Your inputs

Adjust the values to explore a different result.

Enter pre-exponential factor a.
kJ/mol
Enter activation energy in kJ/mol.
K
Enter temperature in K.

Formula

k=A exp(−Ea/RT), with Ea converted to J/mol.
  • Use the units shown beside each field.
  • Results update automatically whenever you change an input.
  • Displayed values use up to four decimal places, or scientific notation for very small or large numbers. Calculations use standard floating-point arithmetic; exact integer and fraction tools identify their own precision rules.
  • Constant activation energy model. The output has the same units as the entered pre-exponential factor.

Example Calculation

Example inputs
  • Pre-exponential factor A: 10000000000
  • Activation energy: 50 kJ/mol
  • Temperature: 300 K

A=10¹⁰ and Ea=50 kJ/mol at 300 K give k≈19.70 in the units of A.

Frequently asked questions

How do I use this calculator?

Enter pre-exponential factor a, activation energy, temperature. The result updates automatically. Use Reset to restore the example values.

What method does it use?

k=A exp(−Ea/RT), with Ea converted to J/mol.. Constant activation energy model. The output has the same units as the entered pre-exponential factor.

Why might a rounded result differ?

The calculation keeps full numeric precision internally, then rounds the displayed result. Rounding intermediate steps by hand can produce a slightly different answer.

Are my inputs saved online?

No. This calculator processes your inputs in your browser. A recently used list stores only calculator names on this device, not your entered values.

Check the assumptions and units before using this result. Read about calculation methods.