---
title: Use and manage variables
seotitle: Use and manage dashboard variables
description: >
  Dashboard variables allow you to alter specific components of cells' queries
  without having to edit the queries, making it easy to interact with your dashboard cells and explore your data.
menu:
  v2_0:
    parent: Visualize data
weight: 101
"v2.0/tags": [variables]
---

Dashboard variables let you alter specific components of cells' queries without having to edit the queries,
making it easy to interact with your dashboard cells and explore your data.

Variables are scoped by organization.

## Use dashboard variables
Both [predefined dashboard variables](#predefined-dashboard-variables) and [custom dashboard variables](#custom-dashboard-variables)
are stored in a `v` object associated with each dashboard.
Reference each variable using dot-notation (e.g. `v.variableName`).

```js
from(bucket: v.bucket)
  |> range(start: v.timeRangeStart, stop: v.timeRangeStart)
  |> filter(fn (r) => r._measurement == v.measurement and r._field == v.field)
  |> aggregateWindow(every: v.windowPeriod, fn: mean)
```

When building Flux queries for dashboard cells, view available dashboard variables
in the **Variables** tab next to the Functions tab.

{{< img-hd src="/img/2-0-variables-data-explorer-view.png" />}}

Click on a variable name to add it to your query and select a value from the **Value** dropdown.

## Predefined dashboard variables
The InfluxDB user interface (UI) provides the following predefined dashboard variables:

#### v.timeRangeStart
Specifies the beginning of the queried time range.
This variable is typically used to define the [`start` parameter](/v2.0/reference/flux/functions/built-in/transformations/range#start)
of the `range()` function.

The **Time Range** selector defines the value of this variable.

#### v.timeRangeStop
Specifies the end of the queried time range.
This variable is typically used to define the [`stop` parameter](/v2.0/reference/flux/functions/built-in/transformations/range#stop)
of the `range()` function.

The **Time Range** selector defines the value of this variable.
It defaults to `now`.

#### v.windowPeriod
Specifies the period of windowed data.
This variable is typically used to define the `every` or `period` parameters of the
[`window()` function](/v2.0/reference/flux/functions/built-in/transformations/window)
in data aggregation operations.

The value of this variable is calculated by dividing the total time within the displayed
time range by the dashboard refresh interval (defined by the **Refresh** dropdown).

## Custom dashboard variables
Create, manage, and use custom dashboard variables in the InfluxDB user interface (UI).

{{< children >}}
