A guide to SIM card sizes

You might not have realised it, but there are actually a few different SIM card sizes available – and the one you need all depends on the type of phone you have.

There’s the standard SIM, which is sometimes referred to as the ‘mini SIM’ and is still used across a range of phones and tablets today, then there are two smaller and increasingly more common SIM card sizes – the micro SIM and the nano SIM.

But what’s the difference between these SIM cards? And which one is right for you?

SIM cards: The basics

Your SIM – or Subscriber Identity Module – is the small plastic card you pop into your phone when you first get it. After that, you’ll probably just forget all about. But, if you decide to upgrade your phone or change your plan, you may need to know about the different SIM card sizes there are.

Essentially, all SIM cards do the same job. Using a built in circuit board, they allow your phone to connect with the network you’re signed up to so you can receive and send calls, texts and data. Every SIM card has its own unique identity, assigned to your contract, so your network knows exactly how to bill you for what you’ve been using.

So, why are there different SIM card sizes?

The only real difference between standard, micro and nano SIM cards are the size – and how this allows them to fit into today’s increasingly slim, compact smartphones.

SIM size Length Width Thickness
Standard SIM 25mm 15mm 0.76mm
Micro SIM 15mm 12mm 0.76mm
Nano SIM 12.3mm 8.8mm 0.67mm

Manufacturers like Apple are keen to make sure the components that go into their gadgets are as small as possible, so they can squeeze even more functionality in. This is why the iPhone has used nano SIM cards since 2012 (iPhone 5), having switched from standard to micro SIMs in 2010 (iPhone 4 and 4S).

But that’s not to say all modern phones and tablets use nano SIM size. There are plenty of gadgets out there that are still using the micro SIM size – and even a few that will have a standard SIM tucked away and working hard. So which one do you need?

SIM card sizes: Which one is right for you?

Apple iPhone and iPad

If you have an iPhone 3GS or older (for example, an iPhone purchased in 2009 or before), you’ll need a standard SIM size. If you have an iPhone 4 or 4S, you’ll want a micro SIM size, and if you’ve an iPhone 5 or anything newer, then a nano SIM will be right for you.

When it comes to network-enabled iPads, it’s even simpler. The first iPad and the iPad 2 both use a micro SIM, but since then all the tablets (Air, Mini and Pro included) have used a nano SIM.

Samsung Galaxy smartphones and tablets

As there are so many more different models out there, it gets a little more complicated with SIM card sizes when talking about Samsung phones and tablets.

In short, the manufacturer introduced nano SIM cards for its Galaxy Alpha and Galaxy A5 smartphones in late 2014. If your phone or tablet was bought after that time, chances are it will need a nano SIM – but there’s no guarantee.

And the rest?

There are phones, smartphones and tablets of all shapes and sizes out there – and they could be using nano, micro, or possibly even standard SIM card sizes.

With that in mind, the easiest way to find out which one you need is to check your user manual. Alternatively, you can always measure the SIM card or SIM card tray inside your gadget and compare it against the guide above.

If you find yourself with the wrong sized SIM card for your phone or tablet, don’t worry, as there are solutions available. You can either contact your network and ask for the right size, or you can adapt the SIM yourself by cutting it or buying an adaptor.

There are a few things to consider if you do decide to cut your SIM card, which you can find out more about in our handy guide. [link]