Measurement of the DA$Phi$NE luminosity with the KLOE detector using large angle Bhabha scattering

We describe the method of measuring the integrated luminosity of the $e^+e^-$ collider DA$Phi$NE, the Frascati $phi-$factory. The measurement is done with the KLOE detector selecting large angle Bhabha scattering events and normalizing them to the effective cross section. The $e^+e^- to e^+e^-(gamma)$ cross section is calculated using different event generators which account for the $O(alpha)$ radiative initial and final state corrections, and the $phi$ resonance contribution. The accuracy of the measurement is 0.6%, where 0.3% comes from systematic errors related to the event counting and 0.5% from theoretical evaluations of the cross section.