It is calculated by dividing the variable net revenues of a property by the total available rooms (see more formulas below).
[1] The difference between ARPAR and other metrics (RevPAR, TRevPAR, GOPPAR) is that it accounts for variable costs and additional revenues.
[2] Various formulas can be used to calculate ARPAR[3] where VarCPOR is variable costs per occupied room The most commonly used formula is: ARPAR accounts for variable costs and additional revenues, thus it reflects the profit (bottom line) versus top line revenue.
GOPPAR accounts for all costs (not only variable) and is retroactive.
ARPAR considers revenues from all departments and only var costs and can be used in forecasts.