# What is ACD (Average Call Duration)?

> ACD (Average Call Duration) is the mean length of answered calls over a period — total talk time divided by the number of answered calls. It is a core voice-traffic KPI: combined with call volume it gives the Erlang load used to size trunks and agents, and alongside ASR it reveals route and service quality. (Not to be confused with an Automatic Call Distributor.) Size capacity with the /tools/erlang-calculator. See /answers/what-is-asr and /answers/what-is-pdd.

- Canonical URL: https://www.broadnet.me/answers/what-is-acd
- Language: en
- Last reviewed: 2026-07-22
- Publisher: BroadNet (https://www.broadnet.me)

## Related

- [All answers](https://www.broadnet.me/answers)
- [Glossary](https://www.broadnet.me/answers)
- [ASR — Answer-Seizure Ratio explained](https://www.broadnet.me/answers/what-is-asr)
- [What is PDD (Post-Dial Delay)?](https://www.broadnet.me/answers/what-is-pdd)
- [What is CPS (Calls Per Second)?](https://www.broadnet.me/answers/what-is-cps)
- [How does programmable voice work?](https://www.broadnet.me/answers/programmable-voice)
- [Erlang calculator](https://www.broadnet.me/tools/erlang-calculator)
- [Voice](https://www.broadnet.me/products/voice)