Call abandon rate calculator
Abandon rate looks simple until you decide what to do with the caller who hung up after three seconds. Enter the contacts offered, answered and abandoned for a period, and how many abandoned inside your short-abandon threshold, and the calculator gives the raw rate, the adjusted rate most centres report, and the answered rate.
Short abandons under 5 s excluded from both sides.
- Abandon rate (raw)
- 8.0%
- Answered rate
- 92.0%
- Offered but neither answered nor abandoned
- 0
Every abandon ÷ every contact offered.
Overflowed, callbacks, or still in queue at period end.
Show the working
- Raw abandon rate = 80 ÷ 1000 offered = 8.0%.
- Adjusted: remove the 15 that gave up within 5 s from both sides: (80 − 15) ÷ (1000 − 15) = 6.6%.
- Answered rate = 920 ÷ 1000 = 92.0%.
Doing this for every interval of the week? Pebble WFM computes the requirement from your forecast and builds the roster. Free month, no card needed.
How abandon rate is calculated
The raw rate is abandoned contacts divided by contacts offered. It is the honest figure and the one to use when comparing against yourself over time.
The adjusted rate removes short abandons, callers who hung up within a threshold of a few seconds. They are mostly misdials, redials and people who realised they rang the wrong line, and they are not a service failure. Remove them from both the numerator and the denominator; removing them only from the abandons flatters the number.
Abandon rate is an outcome of staffing and patience, not a lever in itself. To predict it for a staffing level, or to find the staffing that holds it under a ceiling, use the Erlang A calculator; to reduce it, look at the intervals where the queue was longest, not at the average.
Frequently asked questions
- What is a good abandon rate?
- Under 5 per cent adjusted is the common target for inbound voice; 2 to 3 per cent is good. Above 8 per cent is a staffing problem somewhere in the day, usually in two or three intervals rather than everywhere.
- What threshold should I use for short abandons?
- Five to ten seconds. It should be shorter than the time it takes a caller to hear a greeting and decide to wait; if your IVR is long, measure from queue entry rather than from the call start.
- Should abandoned calls count against service level?
- Yes, if they abandoned after the threshold: that caller was not answered within the target. Excluding them makes service level improve as the queue gets worse, which is the wrong direction.
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