Apple made the decision process for buying a new iPhone a little more challenging this year by releasing both the iPhone 6 and iPhone 6 Plus. The former has a 4.7-inch screen, and the latter has a 5.5-inch screen, leading many users to debate which smartphone is right for them. Not to worry: here are two ways to test which size is right for you.

The first solution is to use this tool made available by The Wall Street Journal to determine whether your hand fits the screen of the iPhone model you wish to purchase. The length of a thumb and index finger will vary between people, making different size smartphones more comfortable for some people than others.

The initial step requires calibrating the tool based on the resolution of your screen, and then proceeding to measure the length of your thumb by approximating a 90-degree angle with your hand on an axis. Then you must measure the distance between the crease of your thumb and the middle joint on your index finger to see how wide your grip is.

You will then want to match your results with small, medium or large smartphone screens as a good reference point:

The small screens category includes the iPhone 5s, iPhone 5c, Moto G, Lumia 1020 and iPhone 4S. The medium screens category includes the iPhone 6, Moto X, LG G2 Mini, Nexus 5, Samsung Galaxy S5 and Sony Xperia Z2. The larger screen category includes smartphones like the iPhone 6 Plus, Samsung Galaxy Note 3, LG G Flex and Lumia 1520.

Looking beyond this simple online test, your best bet is to visit a physical Apple Store if possible. Once you are there, hold the iPhone 6 or iPhone 6 Plus tightly in your hands between your thumb and index finger. Take notice of how less grip you have with the larger model, and determine whether it impacts the comfort of holding it.

Next, hold each smartphone in one hand and perform a swiping motion with your thumb across the screen in an arc style. If your thumb is small and cannot reach much of the screen, then the iPhone 6 is probably your best bet. Just don’t forget that Apple has included a new feature called Reachability for one-handed access to the top of the screen.

Last, don’t forget to perform a simple pocket test. The Wall Street Journal’s Geoffrey Fowler notes that he couldn’t fit the iPhone 6 Plus in virtually any of the jeans pockets that he tried, but your personal mileage may vary.

John Gruber of Daring Fireball gives an interesting opinion about pocketability:

The iPhone 6 Plus, however, makes itself felt in your pants pocket. It is pocketable, at least for me, and I wouldn’t call it uncomfortable. But when I switched back and forth between different phones this week, I’d never forget when the iPhone 6 Plus was in my pocket. (I would sometimes forget whether I had my 5S or the regular 6 in my pocket.) For security purposes I don’t think Apple Stores (or carrier stores) let people try putting display models in their pockets, but in the case of the iPhone 6 Plus, maybe they should. It’s going to be an issue for some.

Ultimately, if the smartphone model you choose isn’t right for you, then rest assured that you have a 14-day return policy at Apple Stores and other resellers to bring it right back.