Rate constants using Arrhenius equation

If I'm trying to use the Arrhenius equation in this form:

$$\ln\left(\frac{k_2}{k_1}\right) = -\frac{E_\mathrm a}R\cdot\left(\frac1{T_2}-\frac1{T_1}\right)$$

And I am given the activation energy ($E_\mathrm a$) in kJ, do I need to convert it into J before I plug in my other givens?

• What are your units for R? – Chet Miller Sep 7 '16 at 23:05
• You just need to make sure the units cancel out with those of the gas constant $R$. If $R$ is in $\mathrm{J~K^{-1}~mol^{-1}}$, then your $E_\mathrm{a}$ should be in $\mathrm{J~mol^{-1}}$ and your temperatures in $\mathrm{K}$. – orthocresol Sep 8 '16 at 2:59