# walkingSpeed A quantity sample type that measures the user’s average speed when walking steadily over flat ground. ``` static let walkingSpeed: HKQuantityTypeIdentifier ``` ## Discussion Walking speed represents how quickly the user walks on flat ground. The system automatically records walking speed samples on iPhone 8 or later. The user must carry their phone near their waist—such as in a pocket—and walk steadily on flat ground. To ensure accuracy, the user’s [`height`](/documentation/HealthKit/HKQuantityTypeIdentifier/height) value must be up to date. The system records 10 to 30 walking speed samples on a typical day. iPhone doesn’t record walking speed samples if the user’s wheelchair status is on. These samples use distance per time units (described in [`HKUnit`](/documentation/HealthKit/HKUnit)) and measure discrete values (described in [`HKQuantityAggregationStyle`](/documentation/HealthKit/HKQuantityAggregationStyle)). For example, the following code shows two ways to create a meters per second unit. The first uses explicit constructors, while the second initializes the unit from a string. ```swift let mps = HKUnit.meter().unitDivided(by: HKUnit.second()) let mpsFromString = HKUnit(from: "m/s") ``` The sample’s [`quantity`](/documentation/HealthKit/HKQuantitySample/quantity) property represents the average walking speed between the sample’s [`startDate`](/documentation/HealthKit/HKSample/startDate) and [`endDate`](/documentation/HealthKit/HKSample/endDate) properties. ## See Also [`HKDevicePlacementSide`](/documentation/HealthKit/HKDevicePlacementSide) Values that indicate the placement of the device that measured a sample. --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)