# Scale Control

![Since v5.2](https://img.shields.io/badge/since-v5.2-green)

This is a React equivalent of Mapbox's [ScaleControl](https://docs.mapbox.com/mapbox-gl-js/api/#scalecontrol).

```js
import * as React from 'react';
import ReactMapGL, {ScaleControl} from 'react-map-gl';

function App() {
  const [viewport, setViewport] = React.useState({
    longitude: -122.45,
    latitude: 37.78,
    zoom: 14
  });
  return (
    <ReactMapGL {...viewport} width="100vw" height="100vh" onViewportChange={setViewport}>
      <div style={{position: 'absolute', bottom: 100, left: 20}}>
        <ScaleControl maxWidth={100} unit="metric" />
      </div>
    </ReactMapGL>
  );
}
```

## Properties

##### `maxWidth` (Number)

- default: `100`

The maximum length of the scale control in pixels.

##### `unit` (String)

- default: `'metric'`

Unit of the distance, one of `'imperial'`, `'metric'` or `'nautical'`.

## Styling

Like its Mapbox counterpart, this control relies on the mapbox-gl stylesheet to work properly. Make sure to add the stylesheet to your page.

## Source

[scale-control.js](https://github.com/visgl/react-map-gl/tree/6.0-release/src/components/scale-control.js)