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QR Code Minimum Size: How Small Can a QR Code Be?

November 10, 2020
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Scott
Table of Contents
Digital Restaurant Table Menu

Using QR codes is fast becoming the norm in a world more and more dependent on contactless interaction. All the QR code statistics bear that out.

But QR codes are only as good as they are reliable. If a QR code won’t scan, everyone’s out of luck. So here’s some information about QR code minimum size. If you’re creating your own QR code, this is invaluable information. (Just keep in mind the QR code security risks of using a free online QR code generator, and check out how to find the best QR code generator.)

Getting your QR code minimum size right is the difference between successfully rolling out an incredibly convenient touchless technology and failure.

In this post we’ll cover:

  • Ideal QR code scanning distance
  • QR code minimum size
  • How big your QR code needs to be
  • QR code resolution requirements
  • How big micro QR codes are

QR Code Distance to Size Ratio

QR codes were designed for a 10:1 distance-to-size ratio. That means the optimal distance of a QR code scanner from a QR code is 10 times the width of the QR code.

In other words, if a QR code is 2" wide, scan it from 20” away.

When making sure your QR code works with a QR code test, scan with this QR code distance to size ratio in mind.

QR Code Minimum Size

The minimum size of a QR code is 2 x 2 cm, or roughly 0.8  x 0.8”. There is no standardized QR code size, and QR codes can actually be smaller than 2 x 2 centimeters. But to make sure the majority of current smartphones can scan it, a QR should be at least 2 centimeters wide by 2 centimeters long.

And to engage in QR code marketing and QR code tracking sufficiently, you typically need a QR code larger than the minimum.

How Big Does a QR Code Need to Be?

We know a QR code should be a minimum of 2 x 2 cm, in general. But that may not be the ideal size for your use case. Here’s how to determine the minimum size for your QR code.

Scanning Distance

How big your QR code needs to be is a function of scanning distance, for the most part. You know a QR code needs a 10:1 distance-to-size ratio. So think about where you’ll place your QR code and what physical constraints that placement may have for the people scanning it. The key is predicting the natural, comfortable scanning distance based on the physical environment.

Let’s use a restaurant as an example. If you place a QR code menu or QR-based digital wine list facing up on a table, people will likely be scanning it from a few inches away. They won’t naturally hold their phone up high off the table surface. On the flip side, place a digital menu QR code template or a QR code on the table or the wall of a 4-6 person booth and it’ll need to be bigger to account for everyone at the table.

Data Amount

Sometimes data amount affects the size of your QR code. Especially when you have a lot of data and you're attempting to print the code at a lower resolution.

At present, there are 40 versions of the QR code. Version 1 is 21 data modules wide x 21 data modules high. Data modules are the little black and white squares that make up QR codes. Version 2 is 25 x 25. And on until version 40, which is 177 x 177. Each version has a higher information capacity than the previous version. Read our How Do QR Codes Work? post for more detailed information about the parts of a QR code.

When you create a QR code, the version used is based on the amount of characters (AKA data) you encode. It can be a lot, which is one of the most defining things about the QR code vs the barcode. The more data, the more rows and columns the QR code has.

For example, let's say you're creating a QR code for a digital menu that's published on the following URL:

https://www.bestrestaurantintheuniverse.com/menu.html

That's 56 alphanumeric characters. It would require a version 3 QR code with 29 x 29 data modules. That's not enough data to warrant straying from the 10:1 QR code distance to size ratio. Read more about QR code versions.

But to ensure scannability with more complex QR codes, they can be made a bit larger. See the "Minimum Size for QR Code Print" section below.

Restaurant Menu Barcode

How Do I Reduce the Size of My QR Code?

To reduce the size of your QR code, you can do three things. Lower the character count, lower the error correction, and remove a central graphic if it exists.

Large QR codes can slow down scanning. Decreasing QR codes keeps them true to their name. The QR code meaning is “quick response code,” after all.

Lower the Character Count

As we saw, the fewer rows and columns a QR code has, the smaller it can be. If you went from URL to QR code, you can shorten the character count by using a shortened version of the URL. That’ll allow you to use a lower version QR code and safely make the QR code smaller.

Error Correction

There are four levels of QR code error correction. The highest level, Level H, stores enough backup data to maintain QR code functionality with up to 30% QR code damage. By using a lower level of error correction, less data modules are taken up for storage. And the QR code can safely decrease in size.

Remove Central Image

Many custom QR codes have a central image or logo. If you’re trying to create a very small QR code, you can do away with optional aesthetic pieces like that. Any room you can clear within the data matrix is valuable real estate.

Minimum Size for QR Code Print

The actual minimum size for scanning ISO 18004-compliant QR codes is 10 mm, which is 1 cm or roughly 0.4”. But, as we said, many modern smartphones need at least double that to reliably scan. Stick with a 2-centimeter minimum and 10:1 distance-to-size ratio when printing or placing your QR code and you’ll be fine.

Unless your QR code is extremely complex and you don’t have the ability to print high-resolution images.

If you don’t have the ability to print high-resolution, here’s a rule for QR code minimum size for large, complicated QR codes. For every 5 rows and columns of your QR code, you can increase its size by about .2” to ensure a 12” scan distance.

You will have to account for this increase in size when you place the QR code, though. But, in the absence of high-resolution printing, this rule ensures that more complex codes remain scannable. 

Below is a QR code table to help you visualize optimal scanning distance based on QR code version. As you can see, the 12” scanning distance increases by .2” for every 5 modules.

QR Code Dimensions

Here’s a QR code chart that shows QR code dimensions and ideal scan distances based on character amount. Again, this is mostly for dense, data-heavy QR codes. Most of the time the 10:1 ratio suffices. Regardless, it’s helpful to visualize how scan distance changes based on the number of data modules.

Version Modules Alphanumeric Characters 6” Scan Distance 12” Scan Distance 18” Scan Distance
2 25x25 47 0.6” 1.2” 1.8”
7 45x45 224 1.0” 2.0” 3.0”
12 65x65 535 1.4” 2.8” 4.2”
17 85x85 938 1.8” 3.6” 5.4”
22 105x105 1460 2.1” 4.2” 6.4”
27 125x125 2132 2.5” 5.0” 7.4”
32 145x145 2840 2.9” 5.8” 10.2”
37 165x165 3729 3.3” 6.6” 13.4”

What Size QR Code for Business Card

The ideal QR code side for business cards is roughly 0.8 x 0.8”. If you use 1 square inch, it’s not the end of the world. The ideal scanning distance just increases a touch. This assumes a standard-sized business card of 9 x 5 cm or 3.5 x 2”.

QR Code Resolution Requirements

A QR code’s minimum resolution should be 76 x 76 px, or 2 x 2 cm. That’s because 1 centimeter is approximately 38 pixels and the minimum QR code size is 2 x 2 cm.

If using imperial measurements, 1 inch is approximately 96 pixels.

How Big is a Micro QR Code?

A micro QR code can be under 1 square centimeter. Micro QR codes were designed by Denso Wave (the same QR code inventor) to be a smaller, more compact version. The smallest micro QR code is 11 x 11 modules and the largest is 17 x 17. The very smallest QR code is 21 x 21 modules. 

So, Just How Small Can a QR Code Be?

QR code minimum size is about 1 x 1 cm—and even smaller if using micro QR codes. But that’s not recommended. 

The practical minimum of a QR code is at least 2 x 2 cm to account for the scanning capability of the majority of modern smartphones and QR code scanner apps. But the ideal size of a QR code is all based on scanning distance and data amount.

For the most part, a 10:1 distance-to-size ratio will work. 90% of the time if you stick to that rule, you’ll be fine. There are edge cases, though. When a QR code needs to be bigger because there’s so much information in it and high resolution printing isn’t available. In that case, use the .2” per 5 modules rule.

If you’re a restaurant replacing single use menus with QR codes, though, all you’ll be encoding is a URL. You won’t need to worry about large, complex static QR codes.