Most companies calculate cost per hire by adding up all recruiting expenses and dividing by the number of hires made in a given period. This usually includes job ads, recruiter salaries, agency fees, interview costs, background checks, referral bonuses, and onboarding expenses. The formula is simple: Total hiring costs ÷ Total number of hires = Cost per hire. In my experience, companies get more accurate numbers when they track both obvious and hidden costs instead of just recruitment ads or agency fees.