How much does T-Mobile’s contract-free iPhone plan save over two years?

Now that T-Mobile offers the iPhone, how do the four national carriers compare in terms of costs? A couple of websites have done the sums.

Our friends over at Zagg did a blog post that suggested three of the four networks come out at exactly the same annual cost when attempting to get as close as possible to like-for-like tariffs, while going with T-Mobile’s contract-free option will save you $580 over two years.

Based on unlimited talk and text, and 4GB of data per month. Sprint offers only ‘unlimited’ data (claiming not to throttle), though is not noted anyway for fast data speeds.

While this is true for individuals, it doesn’t tell the whole story …

The Verge produced a table showing the same figures for an individual (save for a reduced Verizon cost), but it’s quite a different story for couples and families. A couple pays marginally more on T-Mobile than Verizon and AT&T, and a family of four pays even more so.

While there’s no denying that T-Mobile’s new plans are the cheapest around, it’s not the slam-dunk the carrier would have you believe. For a couple of two, it’s about $4,000 for shared data on Verizon and AT&T, or the same price with unlimited data on T-Mobile. You’ll just have to decide what matters to you more — both Verizon and AT&T have much larger LTE networks right now, but you’re stuck in a two-year deal with no real affordable upgrade options, while T-Mobile offers you the promise of being able to escape if you need to or try another phone if you want to. Of course, you’ll need to pay up before you do so — T-Mobile customers have to make up the difference between what they’ve paid so far and their old phone’s retail value if they want to try a new device.

You are going to save on T-Mobile. The question as always is whether the network’s faults (if they do exist) in your geography make the tradeoff worthwhile.