Where to find your data usage on iPhone
Open Settings, then tap Cellular (or Mobile Data on some regions). Scroll down and you'll see Cellular Data Usage, which shows how much data your phone has used since the last time you reset the counter. The number resets automatically on the date you set, usually matching your phone plan's billing cycle.
The total at the top includes all apps combined. Below that, you'll see a breakdown by individual app — which ones are using the most data, and which ones have used data in the background when you weren't actively using them.
This counter measures data used over your cellular connection only. It does not include data used over Wi-Fi, which you can check separately in the same Settings menu.
Key Takeaways
- Your iPhone tracks cellular data usage in Settings > Cellular > Cellular Data Usage, broken down by app.
- The counter resets automatically each month on a date you can set yourself, usually matching your phone plan's billing cycle.
- Wi-Fi data usage is tracked separately and does not count toward your cellular plan limit.
- You can turn off cellular data for individual apps if you want to prevent them from using your plan's data.
- Resetting the counter manually lets you track usage between billing cycles or start fresh at any time.
How to set when your data counter resets
By default, your iPhone resets the data counter on the first day of each month. If your phone plan renews on a different date, you can change this. Go to Settings > Cellular > Cellular Data Options (or Mobile Data OptionsReset Statistics. At the top of that screen, you'll see Reset Period — tap it and choose Monthly, then set the date to match when your plan renews.
Once you set a custom reset date, the counter will automatically zero out on that date each month. This keeps your in-phone counter aligned with what your carrier shows you, so you can track your usage accurately throughout your billing cycle.
Checking Wi-Fi data usage separately
Wi-Fi data does not count against your cellular plan, but your iPhone still tracks how much you use. Go to Settings > Wi-Fi, then scroll down to see which networks you've connected to and how much data you've used on each one. This is useful if you're on a limited home Wi-Fi plan or a metered network at work.
Unlike cellular data, Wi-Fi usage does not reset automatically. You can manually reset it by going to Settings > General > Reset > Reset Network Settings, but this will also forget all your saved Wi-Fi passwords, so use it only if you're willing to re-enter them.
Turning off data for specific apps
If one app is using too much data, you can prevent it from using cellular data without uninstalling it. Go to Settings > Cellular, scroll down to the app name, and toggle off the switch next to it. The app will still work over Wi-Fi, but it won't use your cellular plan when you're away from Wi-Fi.
Some apps, like maps or video streaming, use data heavily. Turning off cellular for these apps is a common way to stay under your plan limit. You can always turn the toggle back on if you need the app to work on cellular later.
Understanding background data usage
Some apps use data even when you're not actively using them — refreshing email, downloading updates, or syncing photos. In Settings > Cellular > Cellular Data Usage, apps that show high numbers despite you rarely opening them are likely using background data.
To stop an app from using data in the background, go to Settings > General > Background App Refresh, find the app, and toggle it off. This prevents the app from refreshing or syncing when you're not using it, which saves both data and battery. You can still open the app and use it normally — it just won't update on its own.
Resetting your data counter manually
If you want to start fresh or check usage between billing cycles, you can reset the counter yourself. Go to Settings > Cellular > Cellular Data Usage, scroll to the bottom, and tap Reset Statistics. This zeros out the total and all per-app numbers immediately.
After you reset, the counter starts from zero again. This is useful if you want to measure how much data you use in a specific week or month, or if you're troubleshooting a data overage and want to see exactly what's happening going forward.
What to do if your data usage seems wrong
Sometimes the number on your iPhone differs from what your carrier shows. This happens because your phone counts data differently than the carrier's network does — your phone may not count some overhead data, or may count it at a different point. A difference of a few hundred megabytes is normal and not a sign of a problem.
If the difference is large — several gigabytes — check whether you've recently reset your counter or changed your reset date. Also check whether you're looking at the right time period: your carrier's billing cycle may not match your phone's reset date. If you're still concerned, contact your carrier and ask them to review your account's data log.
Frequently Asked Questions
Can I see how much data I've used today?
Not directly in the main data usage screen — iPhone only shows a total since the last reset. However, you can manually reset the counter, use your phone for one day, then check the total. Some third-party apps track daily usage, but the built-in method requires this manual reset approach.
Does video streaming count as cellular data?
Yes, if you're streaming over cellular. Video uses data quickly — a one-hour HD video can use 1 to 3 gigabytes depending on quality. If you're on a limited plan, stream over Wi-Fi when possible. You can turn off cellular data for video apps to force them to use Wi-Fi only.
Why is my data usage so high?
Check Settings > Cellular > Cellular Data Usage to see which apps are using the most. Video streaming, social media, and cloud backups are common culprits. Also check Settings > General > Background App Refresh to see if apps are syncing in the background. Turning off background refresh for heavy apps can reduce usage significantly.
Does iCloud backup use cellular data?
By default, iCloud backup only works over Wi-Fi. However, if you manually start a backup over cellular, it will use your data. To prevent accidental cellular backups, go to Settings > [Your Name] > iCloud > iCloud Backup and make sure it's toggled on — this ensures backups only happen over Wi-Fi.
Can I set a data limit or warning on my iPhone?
iPhone does not have a built-in data limit feature that stops you from using more data. However, you can set a reminder by checking your usage regularly in Settings. Some carriers offer apps that send alerts when you're approaching your limit — check your carrier's app store listing to see if they provide one.