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Analytics

Abandon rate

Also called: call abandonment rate

Abandon rate is the percentage of inbound callers who disconnect while waiting in queue, before an agent answers.

Abandonment is the demand that staffing models tend to miss, because Erlang C assumes callers wait indefinitely. Where abandonment is significant, Erlang C over-staffs — models such as Erlang A account for callers hanging up and return lower agent counts for the same service level.

A very short abandon threshold flatters the metric. Calls dropped in the first five seconds are often misdials or callers who changed their mind, which is why many centres report a 'short abandon' figure separately from genuine queue abandonment.

Abandonment is not purely a staffing problem. Queue messaging, position announcements and callback offers all change how long a caller tolerates waiting for the same underlying wait time.

See it in the product

Erlang C staffing calculator

Related terms

Service levelThe share of calls answered within a target time — commonly 80% within 20 seconds. A convention rather than a standard, despite how often it is quoted as one.Average speed of answerThe mean time callers wait in queue before an agent answers. Useful alongside service level, misleading on its own.Call deflectionResolving a customer's need without a human agent — the share of calls an AI agent handles end to end. A core ROI metric for voice AI.Erlang CThe queuing formula that turns call volume and handle time into the number of agents a service-level target needs. The standard basis for contact-centre staffing.

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