Switch your iPhone's distance units in Settings

Your iPhone measures distance in kilometers by default if you set it up in a country that uses the metric system. You can change this to miles in the Settings app without restarting your phone or losing any data. The setting affects Maps, Weather, Fitness, and most other apps that show distance.

Open Settings on your home screen, then tap General. Scroll down and tap Language & Region. At the bottom of that screen, you'll see Measurement System. Tap it and choose US (which uses miles) or Metric (which uses kilometers). Your choice takes effect when ready.

If you don't see a Measurement System option, your region setting may already control this. Go back to Language & Region and check the Region field at the top. If it's set to a metric country like Canada or Australia, changing it to United States will switch everything to miles.

Key Takeaways

  • Open Settings, tap General, then Language & Region to find the Measurement System option.
  • Choose US to see miles, or Metric to see kilometers — the change happens when ready across all apps.
  • If Measurement System doesn't appear, check your Region setting instead, as some iPhone versions tie distance units to region.
  • Maps, Weather, Fitness, and Health apps all respect this setting and will display your chosen unit when ready.

What changes when you switch to miles

Once you set your measurement system to US, every app on your iPhone that displays distance will show miles instead of kilometers. Maps will show route distances in miles, Weather will report visibility in miles, and your Fitness app will log workouts in miles. This includes running, cycling, and walking distances.

The change is system-wide, so you don't have to adjust each app separately. If you travel between countries and need to switch back, you can return to Settings and change it again at any time. Your data and history stay the same — only the unit label changes.

Using miles in Maps and directions

After switching to miles, Maps will show all distances in miles and speed limits in mph. When you search for a route, the turn-by-turn directions will display miles to the next turn. If you're navigating and need to see kilometers temporarily, you can't change it mid-trip — you'd have to go back to Settings.

Some third-party navigation apps like Waze have their own unit settings that don't follow your iPhone's system setting. If you use Waze or another app, check its own settings menu to change units there as well.

Fitness and health tracking in miles

The Health and Fitness apps will record all new workouts in miles once you make the switch. If you've logged workouts in kilometers before, those historical entries stay in kilometers — only new entries use miles. This means your past data remains unchanged, but going forward everything is in miles.

If you use a smartwatch paired with your iPhone, make sure to check the watch's own settings too. Some watches have separate measurement settings that don't sync with your phone's choice.

When your region and measurement system don't match

You can set your region to one country and your measurement system to another. For example, you could live in Canada (which uses metric) but prefer to see miles on your iPhone. Go to Settings, General, Language & Region, and adjust Region and Measurement System separately.

This is useful if you travel frequently or prefer one unit system while living in a country that uses the other. Your choice won't affect anything else — dates, currency, and keyboard layout follow your Region setting independently.

Troubleshooting: Apps still showing kilometers

If you've changed your setting but some apps still show kilometers, restart the app by closing it completely and opening it again. Swipe up from the bottom of your screen (or swipe down from the top right on newer iPhones) to see your open apps, then swipe up on the app to close it.

If the problem persists, restart your iPhone. Hold the power button until you see "slide to power off," then slide to shut down. Wait a few seconds, then press the power button again to turn it back on. After restart, open Maps or Weather to confirm the change took effect.

Frequently Asked Questions

Will changing to miles affect my location or GPS accuracy?

No. Changing your measurement system only changes how distances are displayed to you — it doesn't affect how your iPhone calculates location or how accurate GPS is. Your location data and maps work exactly the same way.

Can I set different units for different apps?

Not through iPhone Settings. Most apps follow your system measurement setting. Some third-party apps like Strava or Waze have their own unit settings in their app preferences, so you can check those individually if you want miles in one app and kilometers in another.

What if I switch between miles and kilometers often?

You can change it as many times as you need by going back to Settings, General, Language & Region, Measurement System. There's no limit to how often you can switch. Each change takes effect when ready across all apps.

Does changing to miles affect my Apple Watch?

Your Apple Watch usually follows your iPhone's measurement setting, but not always. Check your Watch app on your iPhone — go to Privacy and scroll to Health Data to see what units are being used. You can also check the Watch's own Settings app under General, Language & Region.

Will my old workout data convert to miles?

No. Workouts you logged in kilometers stay in kilometers in your history. Only new workouts recorded after you change the setting will be in miles. Your past data doesn't change.