Nano SIM card Size in mm & Inches

A nano SIM measures 12.3 x 8.8 mm and 0.67 mm thick. Officially it is the 4FF (fourth form factor) SIM, standardised in 2012, and it is the smallest removable SIM the industry ever agreed on. Almost every phone released since 2013 uses it.

This guide covers the exact nano SIM dimensions, how much smaller it is than a micro or standard SIM, why the chip itself never changed size, and how the card compares to a fingernail and a grain of rice.

Quick Answer: How Big Is a Nano SIM?

A nano SIM is 12.3 mm long, 8.8 mm wide, and 0.67 mm thick. It weighs about 0.3 grams. The gold contact area is nearly the whole card, because the plastic border that older SIMs carried was trimmed away.

Nano SIM Dimensions at a Glance

• Length: 12.3 mm / 1.23 cm / 0.484 in
• Width: 8.8 mm / 0.88 cm / 0.346 in
• Thickness: 0.67 mm (about 12% thinner than earlier SIMs)
• Contact area: roughly 10 x 8 mm, covering most of the card face
• Weight: about 0.3 g
• Standard: ETSI TS 102 221, 4FF

What Does a Nano SIM Look Like in Size?

A nano SIM is a little smaller than an adult pinky fingernail and about the footprint of the letters “SIM” printed at normal size. It is thin enough to flex slightly between two fingers. Line up 7 nano SIMs end to end and you have roughly the length of a credit card.

6 Everyday Comparisons for a Nano SIM

1. A micro SIM (15 x 12 mm) is about 2.7 mm longer and 3.2 mm wider, and it is thicker.
2. A standard SIM (25 x 15 mm) has more than twice the area.
3. An adult fingernail on the little finger is a close match, roughly 10 – 12 mm across.
4. A grain of long rice (about 7 mm) is a bit more than half the length of a nano SIM.
5. A microSD card (15 x 11 x 1 mm) is slightly larger in every dimension and used to be the common “how small” reference before nano SIMs became normal.
6. A credit card (85.6 mm long) is about 7 nano SIMs laid end to end.

Nano SIM Size in Different Units

Why the SIM Kept Shrinking (and Then Stopped)

Each generation removed plastic, not silicon. The actual chip and its contact pads have been about the same size since the 1990s; what changed was the border around them. The 1FF full-size card, the 2FF mini, the 3FF micro, and the 4FF nano are the same electronics with progressively less trim.

The nano SIM is where removable cards stopped getting smaller. Going further would leave nothing to hold. The next step, eSIM, is not a card at all: it is a chip soldered inside the phone and programmed over the air, so it has no external dimensions.

Common Mistakes When Comparing Nano SIM Size

1. Assuming it is the same thickness as older SIMs. A nano SIM is 0.67 mm, about 0.09 mm thinner than a 2FF or 3FF card. That is why nano trays are shallower.
2. Cutting a micro SIM down with scissors. The contact layout is the same, but a hand-cut card is often too thick and can jam or damage a nano tray.
3. Confusing form factor with capacity. All three sizes can hold the same data; the size is purely mechanical.
4. Thinking eSIM has a “size.” eSIM is embedded silicon, not a removable card.
5. Mixing up length and width. A nano SIM is 12.3 mm on its long side and 8.8 mm on its short side, with one corner clipped for orientation.

Frequently Asked Questions

What are the dimensions of a nano SIM?

12.3 x 8.8 mm, and 0.67 mm thick.

How much smaller is a nano SIM than a micro SIM?

About 2.7 mm shorter and 3.2 mm narrower, and slightly thinner.

Can I cut a micro SIM into a nano SIM?

Physically the pattern lines up, but the older card is thicker and a cut edge is rarely clean, so it can stick in the tray. A proper nano SIM or an adapter is safer.

Is a nano SIM the smallest SIM?

It is the smallest removable SIM. eSIM is smaller still but is built into the phone.

How much does a nano SIM weigh?

About 0.3 grams.

What is 4FF?

“Fourth form factor,” the industry name for the nano SIM.

Do nano and micro SIMs hold different amounts of data?

No. Size is mechanical only; storage and features are unrelated to the form factor.

Final Takeaway

A nano SIM is 12.3 x 8.8 mm and 0.67 mm thick, weighing about 0.3 grams. It is the 4FF form factor, the smallest removable SIM ever standardised, and it works by trimming almost all the plastic away from a chip that has barely changed size in decades. The only thing smaller is the eSIM, which has no dimensions at all.