If you're concerned about how much data your iPhone is using, here's how to check in the iPhone settings and tips on how to lower your usage.

On my iPhone, I can go to Settings > Cellular to monitor data usage for individual apps and turn off mobile data access for those I don't need online all the time.

If you have limited cellular data on your cell phone plan, there's an easy way to check and manage your data usage on an iPhone.

Again, though, cellular data usage is capped at 5GB, and overages cost 5 cents per megabyte. 5GB should be plenty for an average business user sending and receiving e-mail and working with some files.

This guide will show you how to check your smartphone data usage on your Android Phone or iPhone. Data usage is the amount of data that your smartphone uses to connect to the internet.