How many pixels is 35 × 45 mm?

It depends on the DPI. At 300 DPI it is 413 × 531 pixels, at 600 DPI 827 × 1063, and at 200 DPI 276 × 354. Type the mm values here and the tool calculates the pixels for the DPI in the box.

Can I see the pixel numbers before resizing?

Yes. Enter the size in mm, then tap the px unit: the width and height boxes are converted to the same physical size in pixels at the current DPI. Switch back to mm to carry on.

Is the DPI really saved in the file?

For JPG and PNG output, yes: the DPI you typed is written into the file, so printing software reads the photo as 35 × 45 mm rather than as a random size. WebP files have no standard place for it, so a WebP keeps its pixels but carries no DPI.

My form gives mm and a KB limit. What should I do first?

Resize in mm here first, because the millimetres decide the pixel count. If the saved file is then over the limit, run it through the compressor, which lowers JPG quality before it touches the pixel size.

Why does my face look squashed after resizing?

“Stretch” was selected while the photo had a different shape from the mm box. Switch back to “Crop to fill”, the setting this page starts with: the picture keeps its proportions and the surplus is trimmed equally from both sides.

Resize Image in MM for Passport and Visa Photos

Passport and visa offices describe photos the way a printer sees them: 35 × 45 mm, 50 × 70 mm, 33 × 48 mm. A phone photo has no millimetres at all, only a grid of pixels, which is why Paint, Word and most editors leave you guessing. The missing link is DPI, the number of pixels laid down per inch (25.4 mm) of paper.

This page opens at 35 × 45 mm and 300 DPI, the most common passport-photo box. Keep those numbers or type the size from your instructions, and it works out the pixel count, scales the photo to it and stores the DPI inside the JPG or PNG, so a print shop or an image viewer reports the intended size in mm.

Before and after

A steel ruler and a spool of dark thread lying on sheets of tan leather on a workbench — The dashed frame on the left marks the part that fits the new shape. It was scaled to exactly 413 × 531 px, and the left and right edges outside the frame were trimmed.
The file went from 1.30 MB to 77 KB.
The image on the right is the actual file the tool above produced.

The same photo resized to 413 × 531 pixels — The dashed frame on the left marks the part that fits the new shape. It was scaled to exactly 413 × 531 px, and the left and right edges outside the frame were trimmed.
The file went from 1.30 MB to 77 KB.
The image on the right is the actual file the tool above produced.

How to use it

Open the photo you want to bring to a millimetre size; a straight-on portrait with space around the head crops most cleanly.
Leave 35 and 45 in place, or overwrite them with the width and height in mm exactly as your form writes them. Change the DPI only if the instructions name a different value.
“Crop to fill” is already chosen, so a photo of another shape loses an even strip from two edges instead of having the face squeezed. Tick “Lock aspect ratio” only if you want the whole picture kept and one side shorter.
Press Resize, check the pixel size and DPI on the result card, then save the file for printing or upload.

From millimetres to pixels

The sum is: millimetres ÷ 25.4 × DPI, rounded to a whole pixel. At 300 DPI one millimetre is a little under 12 pixels, so a 35 mm side becomes 413 pixels and a 45 mm side 531. At 600 DPI the same photo needs twice as many pixels each way; at 150 DPI half as many. The millimetres on paper stay the same in every case; only the sharpness changes.

That is also why a small source image cannot be rescued by typing a larger DPI. A 300 × 400 pixel crop asked to fill 35 × 45 mm at 300 DPI has to be enlarged by about a third and will print soft. Start from the full-resolution photo and let the tool scale it down.

Photo sizes quoted in mm, with their pixels at 300 DPI

Schengen visa (German Missions in the United States, EU Visa Code standard): 35 x 45 mm, which is 413 × 531 pixels at 300 DPI. Canadian passport (Immigration, Refugees and Citizenship Canada): 50 mm wide x 70 mm high (2 inches x 2¾ inches) printed, which is 591 × 827 pixels; the same page asks for a face 31 mm to 36 mm from chin to crown.

Chinese visa (Embassy of the People’s Republic of China): 33 mm wide x 48 mm high printed; digital 354 (w) x 472 (h) pixels to 420 (w) x 560 (h) pixels. Here the two numbers part ways: 33 × 48 mm at 300 DPI is 390 × 567 pixels, taller than the 560-pixel limit for the online form. Use millimetres for the printed copy and switch the unit to px for the upload. Face-height rules in mm cannot be met by resizing alone; crop the photo so the head fills the right share of the frame first.

Frequently asked questions

How many pixels is 35 × 45 mm?: It depends on the DPI. At 300 DPI it is 413 × 531 pixels, at 600 DPI 827 × 1063, and at 200 DPI 276 × 354. Type the mm values here and the tool calculates the pixels for the DPI in the box.
Can I see the pixel numbers before resizing?: Yes. Enter the size in mm, then tap the px unit: the width and height boxes are converted to the same physical size in pixels at the current DPI. Switch back to mm to carry on.
Is the DPI really saved in the file?: For JPG and PNG output, yes: the DPI you typed is written into the file, so printing software reads the photo as 35 × 45 mm rather than as a random size. WebP files have no standard place for it, so a WebP keeps its pixels but carries no DPI.
My form gives mm and a KB limit. What should I do first?: Resize in mm here first, because the millimetres decide the pixel count. If the saved file is then over the limit, run it through the compressor, which lowers JPG quality before it touches the pixel size.
Why does my face look squashed after resizing?: “Stretch” was selected while the photo had a different shape from the mm box. Switch back to “Crop to fill”, the setting this page starts with: the picture keeps its proportions and the surplus is trimmed equally from both sides.