For the first time ever Apple is competing against Android phablet makers on handset size with the iPhone, as its 2014 models come in two sizes: the 4.7-inch iPhone 6 and 5.5-inch iPhone 6 Plus. However, screen diagonal measurements do not tell the complete story, so if you’re still not sure which model is right for you, then there’s a simple “tool” to use to quickly make your preorder decision easier.

FROM EARLIER: iPhone 6 and iPhone 6 Plus: Pricing, release dates and everything else you need to know

An AppleInsider reader has put together a simple “iPhone 6 Pre-Order Picker,” a PDF document consisting of a single page that shows simple drawings of iPhone 5s, iPhone 6 and iPhone 6 Plus. Once printed on a standard 8.5 x 11 inch printer paper at 100% scale, the “tool” will help you compare the size of your existing iPhone against the iPhone 6 models, and decide which iPhone 6 version to preorder on Friday.

Obviously, if you’re not interested in preordering the iPhone 6 and want to buy it only after a hands-on experience in stores, then you’ll have to wait until September 19th, when the iPhone 6 launches in stores.

For what it’s worth, the 4.7-inch iPhone 6 measures 138.1 x 67 x 6.9mm and weighs 129g, while the 5.5-inch iPhone 6 Plus measures 158.1 x 77.8 x 7.1mm and weighs 172g.

An image showing the “tool” in action follows below.