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# HKMetricPrefix

Prefixes that can be added to SI units to change the order of magnitude.

```
enum HKMetricPrefix
```

## Topics

### Prefixes

[`HKMetricPrefixNone`](/documentation/HealthKit/HKMetricPrefix/none)

A prefix that does not modify the base unit.

[`HKMetricPrefixFemto`](/documentation/HealthKit/HKMetricPrefix/femto)

A prefix that multiplies the base unit by 1e-15.

[`HKMetricPrefixPico`](/documentation/HealthKit/HKMetricPrefix/pico)

A prefix that multiplies the base unit by 1e-12.

[`HKMetricPrefixNano`](/documentation/HealthKit/HKMetricPrefix/nano)

A prefix that multiplies the base unit by 1e-9.

[`HKMetricPrefixMicro`](/documentation/HealthKit/HKMetricPrefix/micro)

A prefix that multiplies the base unit by 1e-6.

[`HKMetricPrefixMilli`](/documentation/HealthKit/HKMetricPrefix/milli)

A prefix that multiplies the base unit by 0.001.

[`HKMetricPrefixCenti`](/documentation/HealthKit/HKMetricPrefix/centi)

A prefix that multiplies the base unit by 0.01.

[`HKMetricPrefixDeci`](/documentation/HealthKit/HKMetricPrefix/deci)

A prefix that multiplies the base unit by 0.1.

[`HKMetricPrefixDeca`](/documentation/HealthKit/HKMetricPrefix/deca)

A prefix that multiplies the base unit by 10.

[`HKMetricPrefixHecto`](/documentation/HealthKit/HKMetricPrefix/hecto)

A prefix that multiplies the base unit by 100.

[`HKMetricPrefixKilo`](/documentation/HealthKit/HKMetricPrefix/kilo)

A prefix that multiplies the base unit by 1000.

[`HKMetricPrefixMega`](/documentation/HealthKit/HKMetricPrefix/mega)

A prefix that multiplies the base unit by 1e6.

[`HKMetricPrefixGiga`](/documentation/HealthKit/HKMetricPrefix/giga)

A prefix that multiplies the base unit by 1e9.

[`HKMetricPrefixTera`](/documentation/HealthKit/HKMetricPrefix/tera)

A prefix that multiplies the base unit by 1e12.

## Relationships

### Conforms To

[`Hashable`](/documentation/Swift/Hashable)

[`RawRepresentable`](/documentation/Swift/RawRepresentable)

[`Sendable`](/documentation/Swift/Sendable)

[`Equatable`](/documentation/Swift/Equatable)

[`BitwiseCopyable`](/documentation/Swift/BitwiseCopyable)

[`SendableMetatype`](/documentation/Swift/SendableMetatype)

---

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