Arrhenius Rate Constant Calculator
Calculate a rate constant using the Arrhenius equation.
Arrhenius Rate Constant measurements
Enter your values, then calculate.
Result
How to calculate arrhenius rate constant
The Arrhenius equation describes how a chemical reaction's rate constant depends on temperature and activation energy — a foundational relationship in chemical kinetics.
How the calculation works
k = A × e^(−Ea/(R×T)), where A is the frequency factor, Ea is activation energy (in J/mol, so kJ/mol values are multiplied by 1000), R is the gas constant (8.314462618 J/(mol·K)), and T is temperature in Kelvin.
Example
A frequency factor of 1×10^13, activation energy of 75 kJ/mol, at 298 K (25°C): k = 1×10^13 × e^(−75,000/(8.314×298)) ≈ 1×10^13 × e^(−30.3) ≈ a very small rate constant, illustrating how sensitive reaction rates are to activation energy at room temperature.
Frequently asked questions
How is Result calculated?
Result = [Frequency factor] × exp( − [Activation energy] × 1000 ÷ (8.3145 × [Temperature])).
Is the Arrhenius Rate Constant Calculator free to use?
Yes — every calculator on Simple Calculator Tools is free, runs in your browser, and does not require an account.
Arrhenius Rate Constant Calculator
k = A × e^(−Ea/(R×T)), where A is the frequency factor, Ea is activation energy (in J/mol, so kJ/mol values are multiplied by 1000), R is the gas constant (8.314462618 J/(mol·K)), and T is temperature in Kelvin.
Let's understand your arrhenius rate constant result.
Calculate a result above and this guide will help you interpret it using this calculator's own formula and explanation.
Pro Tips for Arrhenius Rate Constant
- Temperature must be in Kelvin, not Celsius — forgetting to convert is one of the most common Arrhenius equation errors.
- Small changes in temperature can produce large changes in the rate constant due to the exponential relationship — this is why many reactions speed up dramatically with modest heating.
Common Arrhenius Rate Constant Mistakes to Avoid
- Entering temperature in Celsius instead of converting to Kelvin (K = °C + 273.15), which produces a drastically incorrect result due to the exponential formula.
When to Use This Calculator
The Arrhenius equation describes how a chemical reaction's rate constant depends on temperature and activation energy — a foundational relationship in chemical kinetics.