# Latency percentile calculator

Paste response times and get the percentiles, average and a histogram of how they spread.

## How it works

Percentiles describe what most users experience better than the average, which a few very slow requests pull up.

p95 means 95% of requests were this fast or faster. The slowest 5% are often the ones customers remember.

```
p = value at rank (p ÷ 100) × (n − 1), interpolated
```

## Questions

### Why not use the average?

A handful of very slow requests move the average a lot and hide how most requests behave.

### How many values do I need?

For a stable p99 you need at least a few hundred values; with fewer, treat it as rough.

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