---
title: useBounds
description: "Reads current desktop metrics."
---

```tsx
import { useBounds } from 'filedom';

const metrics = useBounds();
if (!metrics?.calibrated) return null;
```

## Parameters

```ts
useBounds(
  host?: DesktopHost
)
```

`host`: optional host adapter for tests.

## Returns

`SystemMetrics | null`, including `width`, `height`, `iconSize`, and `calibrated`. The value is null until the host first reports metrics. Once metrics are calibrated, the hook also fills in Finder's current icon size and grid spacing.