QR Code Size Guide: What Size Should Your QR Code Be?#

A QR code that's too small is useless. A QR code that's too big wastes space and looks amateur. Getting the size right is the difference between a scan and a lost customer.

I learned this the hard way. The first time I built a QR code feature into a project, I made the demo code 1.5 cm wide and posted it to a Slack channel for testing. Half the team couldn't scan it. Not because the code was wrong — because it was too small for the screens they were scanning from. Size matters, and most people get it wrong.

Here's the exact sizing rules for every common situation, the math behind them, and the other factors that quietly determine whether your code actually works.

The one rule to remember#

The fastest rule is the 10:1 distance-to-size ratio:

Your QR code should be at least 1/10th of the distance from which it will be scanned.

Quick examples:

• Phone in hand at 30 cm → at least 3 cm × 3 cm
• Poster on a wall at 1 m → at least 10 cm × 10 cm
• Room across at 5 m → at least 50 cm × 50 cm
• Billboard from the road at 20 m → at least 2 m × 2 m

That's your baseline. Everything below is about when to go bigger, and why.

Minimum sizes by use case#

Business cards#

Minimum: 1.5 cm × 1.5 cm. Better: 2 cm × 2 cm.

Business card QR codes get scanned at close range (15-25 cm) so they can be small. Below 1.5 cm, older phone cameras start to struggle, especially in the dim lighting of the typical networking event.

Flyers (handheld reading)#

Minimum: 2.5 cm × 2.5 cm (1 inch).

If someone holds the flyer while scanning, the reading distance is around 30 cm. The 10:1 rule gives you 3 cm. Round down slightly to save space, but never go below 2 cm.

Wall posters (1-2 m viewing distance)#

Minimum: 10 cm × 10 cm (4 inches).

Wall posters get scanned from about 1 meter away. 10 cm is the floor. Push it to 15 cm if you want people to scan from further away without leaning in.

Product packaging#

Minimum: 2 cm × 2 cm.

Packaging gets scanned at arm's length (30-50 cm). Keep 2 cm as your floor, but match size to the product. A tiny code on a big box looks lost. A huge code on a small bottle looks crowded.

Restaurant menus and table tents#

Minimum: 3 cm × 3 cm.

Table distance is 40-60 cm. 3 cm gives comfortable scanning on any phone, including older ones. This matters because restaurant patrons aren't going to fight with a scanner — if it doesn't work on the first try, they give up.

Storefront windows#

Minimum: 8-15 cm square.

People on the street are 1-2 meters from the window. If it's a busy street, go bigger — you want people to scan while walking past, not stop and squint.

Billboards and vehicle wraps#

Minimum: 1 meter square, scaled up for distance.

Apply the 10:1 rule strictly. A billboard at 20 meters needs a 2-meter QR code. And honestly, drivers at 50 km/h aren't scanning anyway. Design for stopped traffic or pedestrians.

Print resolution matters as much as size#

Size alone isn't enough. Your QR code also needs to be printed sharp.

• Print minimum: 300 DPI
• Digital screens: 72-150 DPI is fine
• Large format (posters, billboards): 150 DPI can work at distance

If your code looks blurry or pixelated when you zoom in, it won't scan no matter how large it is. Export as SVG when you can — vector scales without loss.

The quiet zone — the invisible margin that breaks codes#

Every QR code needs a quiet zone: a clean blank border around it. The spec requires at least 4 modules. In plain terms:

Leave at least 10% of the QR code's width as empty space on every side.

A 5 cm QR code needs 5 mm of clear space around it. Putting text, borders, or graphics right up to the edge is one of the top reasons real-world QR codes fail.

Error correction levels#

QR codes have four built-in error correction levels that let them still scan when partially damaged, dirty, or covered:

Higher error correction means more modules, which means a more complex-looking code. If you want a logo in the center, use H. For a clean print on a menu, M is fine.

Contrast and color#

• Safest: black code on white background. Always works.
• Works: dark colors on light backgrounds (navy on cream, dark green on pale yellow).
• Risky: light code on dark background. Many scanners struggle with inversion.
• Don't: low-contrast color pairs, gradients across the whole code, codes placed directly on busy photos.

If you're tempted to match your brand colors, test on at least three phones before printing. This is one of those steps that seems unnecessary until you've committed to printing 10,000 flyers with a code that doesn't scan.

How to test before printing#

1. Generate at the final size you plan to print.
2. Print a test copy at the exact size and DPI.
3. Scan from the expected distance with three different phones (iOS and Android, old and new).
4. Scan in low light.
5. Scan at a 30° angle.

If it works in all five tests, ship it. If any one fails, go bigger, increase error correction, or fix contrast.

This takes ten minutes. It has saved me, personally, from a printing mistake I would not want to pay for.

Generate it the right size, the first time#

The Toolatu QR Code Generator exports codes at any size as high-resolution PNG or SVG, with error correction options. No design tool needed.

Tools that help#

Size your QR code correctly once and you stop hearing "it didn't scan" from your customers.