QR Code Size Calculator (Free)

1. 1

   Enter the scanning distance

   How far the phone will be from the code where it is used, such as 40 cm for a table tent or 3 m for a poster. Size for the farthest likely scan.

2. 2

   Say what the code will hold

   A short link, the exact content, a character count, or the QR version if you know it. More content means more modules.

3. 3

   Choose the error correction level

   M suits most printed codes. Choose H if a logo will cover part of the code.

4. 4

   Read the minimum size

   Print the code at least this wide, keep the quiet zone clear on every side, and test a printed proof at the real distance.

The calculator applies the rules from our QR code size guide, so the two always agree. Distances and sizes are in millimetres:

module size = max(0.7 mm, distance ÷ 330)
code width  = max(distance ÷ 10, 20 mm, modules across × module size)
quiet zone  = 4 × module size, on every side
total width = code width + 2 × quiet zone

• The 10:1 rule. A code should be at least one tenth as wide as the distance it is scanned from. It is a printers’ rule of thumb, not part of the QR standard, and it is stated for codes holding a short link, about 25 to 33 modules across.
• The 2 cm floor. Below about 2 × 2 cm, phone cameras struggle to focus close enough, and small print errors merge neighboring modules.
• Module size. Modules should be at least about 0.7 mm for close-up scanning, and grow in proportion to distance beyond that. The calculator uses the module size the 10:1 rule gives a 33-module code (distance ÷ 330); the two limits meet at about 23 cm. Denser codes are made wider so their modules stay that big.
• Modules across. A version v code is 17 + 4v modules across: 21 for version 1, up to 177 for version 40. Pasted content is measured with the open-source qrcode encoder our free generators use, which picks the smallest version that fits. A character count is treated as bytes, as a URL is stored.
• Quiet zone. ISO/IEC 18004 asks for a blank margin 4 modules wide on every side, in the background color.

The result is a starting point, not a guarantee. Light, viewing angle, the phone’s camera, print quality and the surface all shift how well a code reads, so print a proof at size and test it where it will be used.

The same content needs more room as it gets longer. At error correction level M, a 37-character short link is version 3 (29 × 29 modules), a 116-character URL with tracking tags is version 7 (45 × 45), and a 236-character contact card is version 11 (61 × 61).

Error correction moves these numbers too: the 37-character short link becomes version 5 (37 × 37 modules) at level H. See QR code error correction levels for when the extra density is worth it.

The QR standard defines 40 versions. Each holds a fixed amount of data at each error correction level; the table gives the most bytes (letters, digits and symbols in a URL count as one byte each) per ISO/IEC 18004. Content made only of digits fits about 2.4 times as many characters, and content made only of uppercase letters, digits and a few symbols about 1.45 times, because the standard packs them more tightly. Codes for phones are usually version 10 or smaller.

• Measure where people will actually stand. A poster across a room is scanned from further away than one beside a counter.
• Keep the content short. A dynamic code’s short link stays at the same size however long the destination is, so the code can stay small.
• Leave the quiet zone clear: no text, borders, photos or page edges inside it.
• Use dark modules on a light background, and avoid glossy or reflective finishes where you can.
• Export an SVG for print, or a PNG with at least 300 pixels per inch at the final size.
• Print a proof at the real size and scan it with an iPhone and an Android phone, in the real light, before the full run.

Need the code itself? The free QR code generator exports SVG and PNG, and a dynamic QR code keeps a short link inside so you can change where it goes after printing.