---
title: aggregate.rate() function
description: aggregate.rate() calculates the average rate of increase per window of time for each input table.
url: https://docs.influxdata.com/flux/v0/stdlib/experimental/aggregate/rate/
estimated_tokens: 1995
product: Flux
version: v0
---

# aggregate.rate() function

-   Flux 0.61.0+
-   View InfluxDB support

`aggregate.rate()` is experimental and [subject to change at any time](/flux/v0/stdlib/experimental/#experimental-packages-are-subject-to-change).

`aggregate.rate()` calculates the average rate of increase per window of time for each input table.

`aggregate.rate()` requires that input data have `_start` and `_stop` columns to calculate windows of time to operate on. Use `range()` to assign `_start` and `_stop` values.

This function is designed to replicate the [Prometheus `rate()` function](https://prometheus.io/docs/prometheus/latest/querying/functions/#rate) and should only be used with [counters](/flux/v0/prometheus/metric-types/counter/).

##### Function type signature

```js
(<-tables: stream[A], every: duration, ?groupColumns: [string], ?unit: duration) => stream[B] where A: Record, B: Record
```

For more information, see [Function type signatures](/flux/v0/function-type-signatures/).

## Parameters

### every

(Required) Duration of time windows.

### groupColumns

List of columns to group by. Default is `[]`.

### unit

Time duration to use when calculating the rate. Default is `1s`.

### tables

Input data. Default is piped-forward data (`<-`).

## Examples

### Calculate the average rate of change in data

```js
import "experimental/aggregate"
import "sampledata"

data =
    sampledata.int()
        |> range(start: sampledata.start, stop: sampledata.stop)

data
    |> aggregate.rate(every: 30s, unit: 1s, groupColumns: ["tag"])
```

[](#view-example-input-and-output)

View example input and output

#### Input data

| *_start | *_stop | _time | _value | *tag |
| --- | --- | --- | --- | --- |
| 2021-01-01T00:00:00Z | 2021-01-01T00:01:00Z | 2021-01-01T00:00:00Z | -2 | t1 |
| 2021-01-01T00:00:00Z | 2021-01-01T00:01:00Z | 2021-01-01T00:00:10Z | 10 | t1 |
| 2021-01-01T00:00:00Z | 2021-01-01T00:01:00Z | 2021-01-01T00:00:20Z | 7 | t1 |
| 2021-01-01T00:00:00Z | 2021-01-01T00:01:00Z | 2021-01-01T00:00:30Z | 17 | t1 |
| 2021-01-01T00:00:00Z | 2021-01-01T00:01:00Z | 2021-01-01T00:00:40Z | 15 | t1 |
| 2021-01-01T00:00:00Z | 2021-01-01T00:01:00Z | 2021-01-01T00:00:50Z | 4 | t1 |

| *_start | *_stop | _time | _value | *tag |
| --- | --- | --- | --- | --- |
| 2021-01-01T00:00:00Z | 2021-01-01T00:01:00Z | 2021-01-01T00:00:00Z | 19 | t2 |
| 2021-01-01T00:00:00Z | 2021-01-01T00:01:00Z | 2021-01-01T00:00:10Z | 4 | t2 |
| 2021-01-01T00:00:00Z | 2021-01-01T00:01:00Z | 2021-01-01T00:00:20Z | -3 | t2 |
| 2021-01-01T00:00:00Z | 2021-01-01T00:01:00Z | 2021-01-01T00:00:30Z | 19 | t2 |
| 2021-01-01T00:00:00Z | 2021-01-01T00:01:00Z | 2021-01-01T00:00:40Z | 13 | t2 |
| 2021-01-01T00:00:00Z | 2021-01-01T00:01:00Z | 2021-01-01T00:00:50Z | 1 | t2 |

#### Output data

| *_start | *_stop | *tag | _value | _time |
| --- | --- | --- | --- | --- |
| 2021-01-01T00:00:00Z | 2021-01-01T00:01:00Z | t1 | 1.2 | 2021-01-01T00:00:30Z |
| 2021-01-01T00:00:00Z | 2021-01-01T00:01:00Z | t1 | 1 | 2021-01-01T00:01:00Z |

| *_start | *_stop | *tag | _value | _time |
| --- | --- | --- | --- | --- |
| 2021-01-01T00:00:00Z | 2021-01-01T00:01:00Z | t2 |  | 2021-01-01T00:00:30Z |
| 2021-01-01T00:00:00Z | 2021-01-01T00:01:00Z | t2 | 2.2 | 2021-01-01T00:01:00Z |

#### Related

-   [Calculate the rate of change](/influxdb/v2/query-data/flux/rate/)

[transformations](/flux/v0/tags/transformations/) [aggregates](/flux/v0/tags/aggregates/)