What is service level 80/20, how to calculate it in a call centre, and how to reach it
Sado AI team · · 4 min read
In short
Service level 80/20 is the target of answering 80% of incoming calls within 20 seconds. The maths is simple: calls answered within 20 seconds ÷ all calls offered × 100. It isn’t a law but a common call centre convention, so you choose the target. The main mistake is watching the daily average: service level can drop to 50% at a peak hour while the daily figure still looks fine. Measure it in half-hour intervals and staff to them.
What 80/20 means
The first number is a share of calls, the second is seconds. 80/20 means that of 100 calls, at least 80 are answered within 20 seconds. The other 20 wait longer or hang up while waiting.
Other targets exist too: for example, 90/10 where a fast answer really matters, or 70/30 when calls are few and customers will wait. Choose the target by how long your customers are willing to wait.
How to calculate it: formula and example
- Pick an interval, for example 10:00–10:30.
- Count all calls offered in that interval. For example, 60.
- Count how many were answered within 20 seconds. For example, 45.
- Divide: 45 ÷ 60 = 75%. Against an 80% target, this interval is low.
- Agree once how to treat calls dropped in under 5 seconds. Some companies leave them out, since the caller may have dialled a wrong number. Then keep the rule, or weeks can’t be compared.
The numbers are only an example. The data you need, the arrival and answer time of each call, is in your phone system’s report.
Why the daily average misleads
| Interval | Offered | Answered within 20 s | Service level |
|---|---|---|---|
| 09:00–12:00 | 90 | 85 | 94% |
| 12:00–14:00 | 80 | 40 | 50% |
| 14:00–18:00 | 110 | 104 | 95% |
| Whole day | 280 | 229 | 82% |
82% for the day beats the target. Yet at lunchtime every second caller waited more than 20 seconds, and those are the hours when people hang up and call another company. The numbers are only an example.
How to raise service level
- Move lunches and breaks out of peak hours, or stagger them.
- Add a short shift for the peak, for example 11:00 to 15:00.
- Shorten long calls: put frequent answers in the knowledge sheet and AHT falls.
- When the queue is long, offer a callback and keep the promise.
- Size the team with the Erlang C formula or an online calculator: you enter call volume, AHT and the 80/20 target.
Other metrics: call centre KPIs. Building shifts: 24/7 shift schedules.
Service level with an AI operator
Sado’s AI operator answers each call in about a second and handles more than ten calls at once. There is no queue, so on the calls it takes, waiting is 0 seconds, at peak hours and at night.
You can run it alongside your people: for example, the AI takes calls at lunchtime, at night and at weekends, and transfers complex conversations to staff by your rule. More: AI operator for incoming calls; comparison: call centre vs AI operator.
Try it live or call 78 778 01 23 and hear for yourself how fast it answers.
Questions
Is 80/20 a mandatory standard?
No, it is a common call centre convention, not a law. You set the target yourself, based on your business and how long your customers will wait.
How is service level different from answer rate?
Answer rate is how many calls were answered at all. Service level is how many were answered within the target time. A caller answered after 2 minutes counts in the first but not the second.
Does a small business need service level?
Yes, in a simple form: once a week, check how many seconds callers waited at peak hours and how many hung up before an answer. That number shows the hours when you lose customers.
What should callers hear while they wait?
A short message: the company name, “an operator will answer shortly” and, if needed, a callback offer. Skip long adverts and the same tune on repeat: the wait feels even longer.