QR Code Size and Placement Guide: Minimum Sizes, Distance and Testing

For a QR code scanned up close, such as on a business card, badge or product label, the practical minimum is about 2 × 2 cm (roughly 0.8 × 0.8 in), not counting the quiet zone. Smaller codes can work, but only with very little data, sharp printing and phones held close.

Why size is really about modules

A QR code is made of small squares called modules. What a phone camera needs is modules large enough to tell apart. The number of modules depends on the QR code version, which depends on how much data you encode:

• Version 1 is 21 × 21 modules.
• Each version adds 4 modules per side.
• Version 3 is 29 × 29; version 6 is 41 × 41; version 10 is 57 × 57.

Worked example

At 2 cm wide, a version 3 code has modules about 0.69 mm across (20 mm ÷ 29). A version 10 code at the same size has modules about 0.35 mm across (20 mm ÷ 57), which is much harder to scan, especially when printed on textured paper or viewed at an angle. If your code is dense, make it bigger.

Practical minimums

• Business cards, badges, labels (scanned in hand): 2 × 2 cm or more.
• Flyers and table tents (scanned from 20 to 40 cm): 3 to 4 cm.
• Posters and windows: use the distance rule in the next section.

The further away people scan from, the bigger the code needs to be. A widely used rule of thumb is a 10:1 ratio: the scanning distance should be no more than about ten times the code's width.

Size by distance (10:1 rule)

• 20 cm (held in hand): about 2 cm.
• 50 cm (table or counter): about 5 cm.
• 1 m (poster at arm's length): about 10 cm.
• 2 m (wall poster, shop window): about 20 cm.
• 3 m (sign across a room): about 30 cm.
• 5 m (large banner): about 50 cm.

Adjust for real conditions

Increase the size when:

• The code holds a lot of data (a higher version with smaller modules).
• Lighting is poor or the surface is glossy.
• People scan at an angle, such as a sign above a counter.
• The audience includes people with older phones.

You can reduce slightly when the code is a short dynamic link with a simple pattern and people can get close.

Screens and slides

On a projected slide, think about the back row. If the back row is 15 meters from a large screen, the code needs to be large on screen, often a quarter or more of the slide height. Test from the back of the room before the talk.

For ideas on where codes perform best, see 7 places to put your QR code.

More data means a higher QR version with more, smaller modules. At the same printed size, a dense code is harder to scan, so the easiest way to make a code smaller is to put less in it.

Approximate capacity at error correction level M

For binary data such as a URL, QR codes hold roughly:

• Version 2 (25 × 25): up to 26 characters.
• Version 3 (29 × 29): up to 42 characters.
• Version 4 (33 × 33): up to 62 characters.
• Version 6 (41 × 41): up to 106 characters.
• Version 10 (57 × 57): up to 213 characters.

Higher error correction levels hold less data in each version.

Worked example

A long product page address with tracking parameters might run to 100 characters, which needs about version 6 at level M. A short dynamic link of about 25 characters fits in version 2. At 2 cm wide, the version 2 code has modules about 0.8 mm across, against about 0.49 mm for version 6. The short link is far easier to scan.

How to reduce data

• Use a dynamic QR code, which encodes only a short link. Our guide to static vs dynamic QR codes explains the trade-offs.
• Remove unnecessary tracking parameters from static URLs.
• For contact details, link to a digital business card instead of encoding a full vCard in the code.

The quiet zone is the empty margin around a QR code. The ISO/IEC 18004 standard specifies a quiet zone at least four modules wide on all four sides. Without it, phones can struggle to find where the code starts.

How big is four modules?

It depends on the code. For a 2 cm version 3 code with 0.69 mm modules, four modules is about 2.8 mm on each side. For a 10 cm poster code, it is proportionally larger. A simple safe habit: leave a margin of at least one-fifth of the code's width on every side.

What must stay out of the quiet zone

• Text, including your call to action.
• Borders, frames and decorative lines.
• Photos, patterns and background textures.
• The edge of the card, label or page.

Common quiet zone mistakes

• Placing a code tight against the edge of a business card.
• Putting the code inside a colored box with no margin.
• Wrapping text around the code in a layout program.
• Cropping the exported image to save space.

When you export from the QR code generator, the quiet zone is included in the file. Do not trim it off when placing the code in your design.

Use a dark code on a light background with strong contrast. Black on white is the most reliable; brand colors work if the code is clearly darker than its background.

Rules for colored codes

• Dark modules, light background. Inverted codes (light on dark) are not read reliably by every scanner, though many modern phone cameras handle them.
• Strong contrast. Dark navy, deep green or dark purple on white usually works. Mid-tone colors on light backgrounds often fail.
• Avoid gradients across the code and patterned or photographic backgrounds behind it.
• Avoid red-on-white for 1D barcodes, which some laser scanners cannot see; for QR codes, darker reds can work, but test them.
• Mind the finish. Glossy laminates and metallic inks reflect light and can hide modules.

Logos in the middle

A logo in the center covers some modules. The code still scans because of error correction, but only if the logo is small, usually under about 20% of the code area, and error correction is set high enough.

Let the tool check for you

CardDeck's QR code generator includes a contrast check that warns you before you export a code that may not scan. If it warns, darken the code color or lighten the background.

Use level M for plain codes on clean surfaces, and level Q or H when you add a logo or the code may get scratched, dirty or partly covered. Higher levels make the code denser, so they may need a slightly larger print size.

The four levels

QR codes use Reed-Solomon error correction, defined in ISO/IEC 18004:

• L (Low): recovers about 7% of the data.
• M (Medium): about 15%.
• Q (Quartile): about 25%.
• H (High): about 30%.

Choosing a level

• Screens, slides and clean indoor print: L or M.
• Business cards, flyers and general print: M.
• Codes with a center logo: Q or H.
• Outdoor signs, packaging and labels that get handled: Q or H.

The trade-off

Higher error correction stores the same data with more redundancy, which means more modules. A code at level H can be a version or two larger than the same content at level M. If you need level H, keep the content short, which is another reason to use a short dynamic link.

CardDeck keeps error correction high enough that codes with a center logo still scan.

Place QR codes on flat, well-lit surfaces at a comfortable height, where people pause and can get close enough to scan. Tell them why to scan with a short label.

Placement rules

• Flat surfaces. Avoid folds, seams, creases and tight curves such as narrow bottles. A curve distorts the grid.
• Comfortable height. For walls and windows, roughly between waist and eye level.
• Good light, no glare. Avoid spots under direct lights or behind reflective glass, or use a matte finish.
• Where people pause. Counters, tables, queues, seats and badges.
• Away from edges. Keep the quiet zone clear of trims and folds.
• A short label. "Scan to save my contact", "Scan for the menu".

Placement by item

• Business cards: on the back, at least 2 × 2 cm. See QR code business cards.
• Event badges: near the bottom edge, where a lanyard will not cover it.
• Packaging: on a flat panel, away from the retail barcode.
• Posters: lower half of the poster, at a height people can reach with a phone.

Places to avoid

Moving vehicles, roadside billboards, signs above head height, and anywhere people cannot stop safely.

Test the code at its real printed size, on real phones, at the real scanning distance. A test on your monitor is not enough.

Testing checklist

1. Print a proof at final size on the actual material or something close to it.
2. Scan with at least two phones: an iPhone and an Android, ideally including an older model.
3. Scan at the expected distance and angle, not just close up and straight on.
4. Check the light: scan under the lighting where the code will be used.
5. Confirm the destination: the right page opens, loads quickly on mobile data and works on a small screen.
6. Check dynamic redirects: if the code is dynamic, confirm the redirect and that scans appear in analytics.
7. Test the logo version if you added one, separately from the plain version.

Bulk and batch codes

When you generate hundreds of unique codes from a spreadsheet with the bulk QR code generator, test a sample from the beginning, middle and end of the batch, and check that each opens the right destination.

Common mistakes

• Testing only on screen.
• Shrinking the code at the last minute to fit the layout.
• Trimming the quiet zone.
• Printing a static code to a URL that later changes.
• Forgetting the call to action.