We have formulated an empirical analytic model for the static characteristics of implanted vertical-cavity surface-emitting lasers (VCSELs). Specifically, we have derived analytic formulas for the threshold current, slope efficiency, dynamic resistance, and the output power and forward voltage at the operation current of 12 ㎃ in terms of the implant and metal-aperture radii by fitting the measured results. The radii of the metal aperture and implant mask of the 850 nm VCSELs range from 4 to 12.5 ${mu}{ extrm}{m}$ and 7 to 17.5 ${mu}{ extrm}{m}$ respectively. The model shows the way of tailoring the VCSEL characteristics by changing the mask dimensions only.