Sim Cards

SIM card sizes and types explained

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If you’ve got a phone, then you’ll need a SIM – whether that be a physical SIM card or an eSIM. And signing up to a new SIM only phone plan has never been easier, with some amazing deals out there. However, there are still some confusing points about buying a new phone plan, including knowing which type of SIM card you need, and the varying SIM card sizes.

In this Canstar Blue review, we’ll look at the different types of SIM cards.

SIM card sizes

As smartphone technology is advancing, SIM card sizing is reducing. This is because the space inside a phone is valuable and if manufacturers can cut down on the size of SIM cards, they can make room for the more important parts – such as bigger batteries or more powerful processors. But this is not to say that the bigger SIM cards are not being used in some smartphone models and so it’s worth knowing what different sizes of SIM card are out there.


The three different sizes of SIM cards in use are:

  • Mini (also known as standard)
  • Micro
  • Nano

Standard SIM Cards

Standard SIM cards are the biggest SIM you’ll see these days, and are mostly used in larger devices which are concerned more with ease of use than saving space. They’re found in budget mobile phones and other devices with thicker profiles. The Standard SIM card has been around since the late 1990s, and measures 25mm x 15mm – about the size of your top thumb joint.

Micro SIM Cards

Micro SIM cards are probably the second-most common SIM card size in use today, and were introduced in 2003. Roughly half the size of a Standard SIM at 15mm x 12mm (but using the same-sized circuit), Micro SIMs are used in many Android mobile phones – particularly those from Samsung. In recent years, micro SIM cards have also started to be phased out in favour of Nano SIMs.

Nano SIM Cards

A size which originated with the iPhone 5’s tiny SIM card slot, the Nano SIM size is fast becoming the standard size for new smartphones. The Nano SIM is almost all circuit with hardly any plastic bezel, measuring just 12.3mm x 8.9mm, and making it ideal for saving space as modern phones grow ever thinner.

Read more: What is an eSIM?

SIM Card Sizes Compared

SIM Card Type Length (mm) Width (mm) Height (mm)
Mini 25.00 15.00 0.76
Micro 15.00 12.00 0.76
Nano 12.30 8.80 0.67

What’s the difference between SIM card sizes?

Apart from the physical size of the SIM cards, there isn’t any difference Mini, Micro and Nano SIM cards. Each are capable of doing the same job, but are simply different sizes to fit into compact phone models.

What size SIM card do I need?

Sim card

The SIM card you will need depends entirely on your mobile phone. You can find out the size of your phone’s SIM card in several ways, including:

  • Checking your phone’s user manual.
  • Going to the manufacturer’s website and checking the tech specs of your phone.
  • Pull out the SIM card holder and measure it.
  • Compare it to your existing SIM card.

Fortunately, just about all mobile service providers understand your predicament and will send you a 3-in-1 SIM card when you subscribe. The Micro and Nano SIM sizes are contained within the Standard SIM, and all you need to do is pop out the one you’d like to use (i.e. the one that fits), and is otherwise known as a ‘combi SIM’. And, in some cases, you won’t even need to worry about equipping a SIM card at all, with some phones coming with a preinstalled eSIM, although it’s only available on select models.

And if you’re looking for a new SIM card, check out our guide on where to buy SIM cards, or how to active a SIM card once you’ve purchased it to help you get your phone up and running.

Compare SIM-only phone plans

Here is a selection of postpaid plans from Canstar Blue’s database with a minimum of 20GB of data, listed in order of standard cost, lowest to highest, then by data allowance, largest to smallest. Try using our mobile phone plan comparison tool to see a wide range of plans from other providers. This table includes products with links to referral partners.

Here is a selection of prepaid plans from Canstar Blue’s database with a minimum of 10GB of data each month, listed in order of standard cost, lowest to highest, then by data allowance, largest to smallest. If you want to compare a larger range of offers from other providers, use our phone plan comparison tool. This table includes products with links to referral partners.

Compare SIM Only Plan Providers

Original Author: Sam Bloom

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