Precise luminosity determination at CMS

Precise luminosity calibration at bunched-beam hadron colliders like the Large Hadron Collider (LHC) is critical to determine fundamental parameters of the standard model and to discover or constrain beyond-the-standard-model phenomena. The results of luminosity determination at LHC interaction point 5 with the Compact Muon Solenoid (CMS) detector, using proton-proton collisions in 2018, is reported. The calibration is derived by analyzing the data of the van der Meer (vdM) scan program. The total uncertainty is 2.5\% (similar to previous years) and dominated by the contributions due to the x-y factorization assumption and luminometer linearity.