Already printed your passport photo? Upload a scan or phone photo of the sheet, calibrate the scale with anything of known length (a ruler, or a bank card’s long edge), then box the photo and read its true width and height in millimetres. Everything runs in your browser — nothing is uploaded.

Load an image, then calibrate before measuring.

How it works

1. Upload the printed sheet. Scan it, or photograph it flat, so the photo edges and your ruler are both visible.
2. Calibrate. Press Calibrate, click the two ends of something whose real length you know, and type that length in millimetres. A ruler segment is ideal; a bank card’s long edge is 85.6 mm. This sets how many pixels equal one millimetre.
3. Measure. Press Measure, drag a box around the printed photo, and press Check size. The tool converts the box to millimetres and compares it with the target.

The tool will not guess a size without calibration — a scan can be at any resolution, so pixels alone say nothing about millimetres.

Why prints come out the wrong size

Most home printouts of passport photos are silently shrunk: “Fit to page” is the default in many print dialogs, and a 35 × 45 mm photo printed at 95% is a wrong-size photo. A print that should measure 35 mm can come out a millimetre or two light, which is exactly the sort of error a border officer or an applications clerk can reject. Use the print calibration sheet to check the printer before you print, and this tool to confirm the result after. If the print is off, re-layout and reprint from the passport photo print sheet.

What counts as true size

The comparison allows a 0.5 mm tolerance in each direction, which covers normal printer and paper variation. Inside that, the print is reported as true size; outside it, you get the deviation as a percentage and whether the print came out too large or too small. The target list matches the common standards — 35 × 45 mm, 2 × 2 in, Canada’s 51 × 51 mm and more — and you can type a custom width and height for anything else. For the exact figure a country wants, see the photo size chart.

Frequently asked questions

How do I check a printed photo is the right size?
Scan or photograph the printed sheet, calibrate the scale by marking something of known length and entering its real millimetres, then box the photo. The tool converts the box to millimetres and compares it with your target size.

Why do I have to calibrate first?
Because a scan or phone photo has no fixed scale — one image might be 300 pixels per inch and another 600. Without a known-length reference the pixels cannot be converted to millimetres, so the tool refuses to report a size until you calibrate.

What can I use as a reference?
Anything whose real length you know: a ruler segment is ideal, and a bank card’s long edge is 85.6 mm. Mark its two ends, then type the real length in millimetres.

What tolerance does it use?
It allows 0.5 mm in each direction, which covers normal printer and paper variation. Outside that it reports the deviation as a percentage and whether the print is too large or too small.

My print is too small — what now?
Reprint at a corrected scale: check the printer with the calibration sheet first, then re-run the layout from the print sheet at 100% (not “Fit to page”).

Is the upload private?
Yes. The image is read locally with the browser’s canvas and is never sent anywhere; the tool works offline once the page has loaded.

Related: Print Calibration Sheet · Passport Photo Print Sheet · photo size chart · printing guide · Image Cropper · Passport Photo Checker · all tools

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