QR Code Size Guide: How Big Should Your QR Code Be?
The size of a QR code has a direct impact on whether it scans reliably in real-world conditions. Too small and the camera cannot resolve the individual modules. Too large and it overwhelms the design. The right size depends on the medium (print vs. screen), the expected scanning distance, the amount of data encoded, and the printing resolution. This guide gives you specific size recommendations for every common use case, from business cards to billboards.
The Fundamental Rule: Size vs. Scanning Distance
The minimum scan distance for a QR code depends on its physical size and the density of the encoded data. A widely cited rule of thumb in the QR industry is that the minimum comfortable scanning distance equals 10 times the physical width of the code. This comes from the optics of smartphone cameras — most phone cameras can resolve detail at roughly a 1:10 ratio of subject width to distance. A 2 cm code is scannable from about 20 cm away. That is fine for a business card held at arm's length. A 5 cm code is scannable from about 50 cm — good for a counter-top display or magazine page. A 10 cm code is scannable from about 1 meter — suitable for a retail shelf edge or a small poster. A 30 cm code is scannable from about 3 meters — suitable for a floor stand, a window display, or a small billboard. Think carefully about the context in which your QR code will actually be scanned. A poster on the back wall of a trade show booth may be 2–3 meters from potential scanners. A QR code on the wall of a train station is scanned by people standing 1–2 meters away. A table card in a restaurant is scanned from 30–60 cm. The rule breaks down if the data in the code is very dense (long URL, vCard with many fields). A dense code has more modules packed into the same area, making each module smaller and harder to resolve. If you have a long URL, shorten it first, then apply the size rule. Alternatively, use a larger code to compensate for the higher module density.
Print Size Recommendations by Use Case
Here are specific minimum and recommended sizes for common print applications, based on the 10:1 scanning distance rule and standard print quality. Business cards (85×55 mm): Minimum 15 mm × 15 mm. Recommended 20 mm × 20 mm. Place on the back of the card with a white background and a quiet zone. At 300 DPI, a 20 mm code requires a 236 pixel PNG — our tool's 256 px option is ideal. Flyers and A5 brochures: Minimum 25 mm × 25 mm. Recommended 35 mm × 35 mm. These materials are typically held in hand and scanned from 30–50 cm. Larger codes give more margin for error if the paper gets slightly bent or the printing is not perfect. A4 posters and event programs: Minimum 30 mm × 30 mm. Recommended 40–50 mm × 40–50 mm. Wall-mounted posters may be scanned from 60–80 cm. Large format posters (A1, A0): Minimum 60 mm × 60 mm. Recommended 80–100 mm. Viewers approach these from 1–2 meters. Billboards and OOH advertising: The code should be large enough to scan from the expected pedestrian or passenger distance. A bus shelter poster viewed from 1 meter needs at least a 10–12 cm code. A large roadside billboard should generally not use a QR code unless there is a very slow-traffic or stationary viewing context — drivers cannot safely scan at speed. Product labels: Minimum 15 mm × 15 mm for small products. Use 20–25 mm whenever space allows. Labels may be scanned in poor supermarket lighting or under harsh warehouse lighting.
Screen Size Recommendations
For digital displays, QR codes face different challenges than print. Screen brightness and glare can interfere with scanning. Refresh rates on some displays cause banding effects that confuse camera sensors. And the expected screen-to-phone distance varies widely. For websites and web apps, the minimum recommended size for an embedded QR code is 200×200 pixels. At typical desktop viewing distances (50–70 cm), a 200 px code on a standard monitor is about 5–7 cm wide — well within the reliable scanning range. For mobile screens showing QR codes to be scanned by another device, use at least 150×150 CSS pixels. For emails, embed QR codes at 200×200 px minimum. Many email clients display images at 1:1 pixel mapping without scaling, so use the actual display size rather than relying on CSS scaling. For presentation slides and video conferencing: if the QR code will be screenshared or projected, use at least 300×300 px and ensure there is a white background around the code in the slide design. On a projector screen viewed from 5–10 meters, a QR code that is less than 15–20 cm wide will be unreadable. For digital signage (TV screens, interactive kiosks): scale based on the screen size and expected viewer distance. A 55-inch screen at 1.5 meters viewing distance should have a code at least 200×200 px in a 1080p asset, which renders at about 12 cm on screen. For 4K assets, multiply the pixel dimension by 2 for the same physical size. Our tool generates codes from 128 to 1024 pixels. For all digital uses, 256 or 512 px is sufficient. For print, always use 512 or 1024 px to ensure you have resolution to spare.
How Data Density Affects Required Size
One factor that is often overlooked in QR sizing guides is data density — the relationship between how much data you encode and how large the resulting code must be to remain scannable. A QR code for a short URL like https://example.com (20 characters) might generate a version 2 code (25×25 modules). At a 1 mm module size, the physical code is 25 mm square — perfectly readable at moderate sizes. A QR code for a long URL like https://www.example.com/product/category/item?ref=homepage&utm_source=print&utm_campaign=spring2026 (95 characters) might generate a version 5 or 6 code (37×41 modules). The same 1 mm module size gives a 37–41 mm physical size. But more importantly, the denser pattern means each module is smaller at the same print size, requiring either a larger print size or a longer scan distance. A full vCard with five or six fields encoded in byte mode can reach 200–400 characters, potentially requiring a version 10 or higher code (57+ modules per side). This needs to be printed significantly larger than a short URL code for the same scan reliability. The practical implication: always shorten URLs before encoding them if the printed size is constrained. A URL shortener can take a 100-character URL down to 20–25 characters, dropping the QR version by several steps and producing a noticeably cleaner, more scannable code at small print sizes. Our tool generates whatever version is required for your input length. If the generated code looks very dense (lots of tiny modules), consider shortening the input data and regenerating.
Frequently Asked Questions
- What is the minimum size for a QR code on a business card?
- The practical minimum is 15 mm × 15 mm for a short URL at error correction level L. For a vCard or longer URL, use at least 20 mm × 20 mm. Print the code with maximum contrast (black on white or dark brand color on white) and ensure the quiet zone is intact. Test the printed card by scanning it indoors under typical office or restaurant lighting — not just in bright daylight.
- How large should a QR code be on an A4 poster?
- For an A4 poster viewed from roughly 50–80 cm away, aim for a QR code of 40–60 mm square. This gives comfortable scanning distance headroom. Position it with a clear white background and a call-to-action line above or below it. If the poster is intended for display behind a counter or on a wall where viewers will approach from 1–1.5 meters, increase to 70–80 mm.
- Does QR code size affect how much data it can store?
- Physical print size does not directly affect data capacity — the data capacity is determined by the QR version (the number of modules in the grid). However, a larger physical size makes each module larger, which makes the code easier to scan reliably at a given data density. If you need to encode a lot of data, you can still use a small physical code but scanning reliability will be lower. Shortening the data payload reduces the QR version and the module count, which improves reliability at any given physical size.