Arrhenius Equation Calculator
Calculate a reaction rate constant from activation energy, temperature, and the pre-exponential factor.
Scientific notation allowed (e.g. 1e10).
Rate constant k
Exponent −Ea/(RT)
Rate constant k
Calculation Steps
The Arrhenius Equation
The Arrhenius equation describes how the rate constant of a chemical reaction depends on temperature and activation energy. As temperature rises, more molecules possess enough energy to overcome the activation barrier, so the rate constant increases.
k = A · e^(−Ea / (R · T))
- • k = rate constant
- • A = pre-exponential (frequency) factor
- • Ea = activation energy (converted from kJ/mol to J/mol)
- • R = gas constant = 8.314 J/(mol·K)
- • T = absolute temperature (K)
Note: The units of the rate constant k match the units of the pre-exponential factor A and depend on the reaction order. Temperature must be given in kelvin, and activation energy is entered in kJ/mol (the calculator converts it to J/mol internally to match the gas constant R = 8.314 J/(mol·K)).