Abandonment rate
Abandonment rate is the percentage of incoming calls in which the caller hangs up before being answered, usually while ringing or waiting in a queue.
Also called: abandoned call rate, call abandonment, hang-up rate
It is calculated as abandoned calls divided by calls offered, often excluding calls dropped within the first few seconds (misdials). It rises with wait time: the longer callers sit in a queue, the more of them leave. Some centers also count calls abandoned during an IVR menu.
Abandoned calls are the invisible part of a missed-call problem. The phone did ring, the caller was there, and there is no message to return. For a business that gets most of its inquiries by phone, abandonment rate is close to a direct measure of lost leads.