Know your data needs
Most of today's plans are priced for data usage, not for talk or text. What you really need to know when choosing a plan is how much data you're going to use so you don't overspend.
Start by examining your usage from recent bills. You can also use online data estimation calculators, which ask how much you use your smartphone for everything from email to social media to app downloads. But these calculators assume you'll use cellular data for everything. You can significantly cut down on data usage by using Wi-Fi at home.
It's also crucial to understand how any plan you're considering defines "unlimited data."
According to a WhistleOut.com search, the least expensive option for getting 3GB of data, a $25-per-month plan from GIV Mobile, provides unlimited data at relatively slow 2G speeds. For $60 a month, "unlimited" means you get significantly faster 4G LTE speeds, the best available.
For any plan that isn't unlimited, find out what happens if you go over your data allotment. Some carriers reduce data speeds, while others charge extra for going over.
Some plans offer rollover data or monthly refunds for unused data. With others, you're overpaying for service you're not using.