# Apdex score calculator

Turn response times and a target threshold into an Apdex score from 0 to 1, with a rating.

## How it works

Requests at or under the target T count as satisfied, up to four times T as tolerating, and anything slower as frustrated. Tolerating requests count half.

```
Apdex = (satisfied + tolerating ÷ 2) ÷ total
```

## Questions

### What target should I use?

Pick the time at which users stop noticing a delay for that page or call, often 300 to 500 ms for APIs.

### What is a good score?

0.94 and above is excellent, 0.85 good, 0.7 fair and below 0.5 unacceptable.

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