# What is MOS (Mean Opinion Score)?

> MOS (Mean Opinion Score) is the standard measure of voice call quality, rated 1 (bad) to 5 (excellent). 4.0 and above is toll quality; below 3.5 is noticeably degraded. Originally a human listening test, MOS is now usually estimated automatically (per ITU-T models) from measured latency, jitter, and packet loss. It is the single number carriers use to compare routes and diagnose a poor call path. See /answers/voip-quality, /answers/what-is-jitter, and /products/voice.

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

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