How to Change km to Miles on iPhone: A Complete Settings Guide

Whether you've moved countries, bought a used car with an unfamiliar odometer display, or simply prefer imperial measurements, knowing how to switch your iPhone from kilometers to miles is genuinely useful. The good news: iPhones don't use a single universal "units" toggle. The measurement system you see depends on which app or feature is displaying the distance — and each has its own setting.

Here's a clear breakdown of where those settings live and what affects them.

Why Your iPhone Shows Kilometers in the First Place

iPhones default to the measurement system tied to your region settings. If your iPhone is set to a country that uses the metric system — which is most of the world — apps like Maps, Health, and Fitness will display distances in kilometers by default.

This is controlled at the operating system level through Language & Region settings, but changing it there doesn't always cascade to every app automatically. Some apps read the system setting; others have their own independent unit preference. That's the key variable most guides miss.

📍 Changing Units in Apple Maps

Apple Maps reads your region settings by default, but you can override the distance unit directly:

1. Open the Settings app
2. Scroll down and tap Maps
3. Under Distances, select In Miles

This changes the turn-by-turn navigation readouts and distance callouts within Apple Maps only. It won't affect other apps.

🏃 Changing Units in the Health App

The Health app tracks walking, running, and cycling distances. It pulls its default from your region, but you can change it:

1. Open the Health app
2. Tap your profile icon (top right)
3. Tap Unit Settings
4. Select the relevant metric — such as Distance or Walking + Running Distance
5. Change the unit to Miles

Each data type (distance, weight, height) has its own unit setting here, which means you can mix and match — showing weight in pounds but height in centimeters, for example.

🚴 Changing Units in the Fitness App

If you use the Fitness app with an Apple Watch, workout distances are set through the Watch app on your iPhone:

1. Open the Watch app
2. Tap My Watch, then go to Workout
3. Select Units of Measure
4. Set running, cycling, or swimming distances to your preferred unit

Apple Watch and the Fitness app share these settings, so changing them here updates your workout summaries on both devices.

Changing the System-Wide Region Setting

If you want the broadest possible effect — shifting the default across all Apple apps and any third-party apps that respect iOS system settings — change your region:

1. Open Settings
2. Tap General → Language & Region
3. Under Region, select United States (or another country that uses miles, such as the United Kingdom for most road distances)

Important caveats here. Changing your region affects more than units. It can alter:

• Date and time formats (MM/DD vs DD/MM)
• Currency display in some apps
• App Store content availability in edge cases
• First day of the week in Calendar

Some users change the region purely for unit purposes and don't notice side effects. Others find the formatting changes disruptive. It depends entirely on how you use your device.

Third-Party Apps Have Their Own Rules

Apps like Google Maps, Strava, Garmin Connect, or Nike Run Club do not always inherit iOS system settings. Each has its own unit preference buried in its own settings menu. The path varies by app, but look for:

• Profile → Settings → Units (common in fitness apps)
• Account → Preferences → Measurement (common in navigation apps)

If you've changed your iOS region and a third-party app is still showing kilometers, that app is almost certainly using its own internal setting rather than reading from iOS.

A Quick Reference: Where Each Setting Lives

What Actually Determines Which Setting You Need

The right path depends on a few factors that vary from person to person:

Which apps you use most. A runner using Strava daily needs to change Strava's internal setting — adjusting Apple Health won't help them during a run. A driver relying on Apple Maps needs the Maps setting specifically.

Whether you want a partial or full switch. Some users want miles only in navigation but don't mind kilojoules or kilograms elsewhere. The per-app approach supports that. Others want everything consistent, which points toward the region setting combined with per-app overrides.

Your iOS version. The exact menu paths described here reflect iOS 16 and later. Earlier versions have similar options but the navigation occasionally differs — the Language & Region path, in particular, has moved around across major iOS versions.

Shared devices or Family Sharing. If your iPhone is used by multiple people or linked to a family member's Apple Watch, changing system-wide region settings or Health unit preferences affects the shared data too.

The technical steps are straightforward — but which combination of settings actually makes sense depends on your apps, your habits, and how consistent you want your unit display to be across your device.