Modified Kramers formulas for the decay rate in agreement with dynamical modeling

► Accuracy of the Kramers approximate formulas for the thermal decay rate is studied. ► It is shown that the Kramers rate deviates sometimes from the exact one by up to 20%. ► Corrections to the Kramers formulas are obtained. ► Corrected Kramers rate agrees with the exact one typically within 2%. ► The corrections derived for overdamping, work well in the case of medium friction.