Calculated billings = Revenue + Change in Deferred Revenue. It is used as a proxy for bookings and cash flow activity when actual booking data is not disclosed. A rising billings number signals strong sales momentum.

Example: A SaaS company reports $3M in revenue for the quarter. Deferred revenue grew from $4M to $5.5M. Calculated billings = $3M + $1.5M = $4.5M, indicating that the company invoiced $4.5M worth of contracts during the quarter.