---
title: Characteristic Units
framework: homekit
role: collectionGroup
role_heading: API Collection
path: homekit/characteristic-units
---

# Characteristic Units

Descriptions of the units of a characteristic.

## Overview

Overview Expect to find one of these values in the units property of a characteristic’s metadata.

## Topics

### Parts Per Total

- [HMCharacteristicMetadataUnitsPercentage](homekit/hmcharacteristicmetadataunitspercentage.md)
- [HMCharacteristicMetadataUnitsPartsPerMillion](homekit/hmcharacteristicmetadataunitspartspermillion.md)

### Temperature

- [HMCharacteristicMetadataUnitsCelsius](homekit/hmcharacteristicmetadataunitscelsius.md)
- [HMCharacteristicMetadataUnitsFahrenheit](homekit/hmcharacteristicmetadataunitsfahrenheit.md)

### Time

- [HMCharacteristicMetadataUnitsSeconds](homekit/hmcharacteristicmetadataunitsseconds.md)

### Light

- [HMCharacteristicMetadataUnitsLux](homekit/hmcharacteristicmetadataunitslux.md)

### Mass

- [HMCharacteristicMetadataUnitsMicrogramsPerCubicMeter](homekit/hmcharacteristicmetadataunitsmicrogramspercubicmeter.md)

### Rotation

- [HMCharacteristicMetadataUnitsArcDegree](homekit/hmcharacteristicmetadataunitsarcdegree.md)

## See Also

### Specifying units

- [units](homekit/hmcharacteristicmetadata/units.md)