Tool StudioResize to an exact size — pixels, cm, mm, or inches
Upload your image
Drag and drop or browse for a file.
Set the size
Pick pixels, cm, mm, or inches, then type the size — for cm, mm, or inches, set a DPI too (300 works for most print and passport-photo uses).
Download
Get your resized image as PNG or JPEG, sized exactly.
Government portals, job applications, and passport forms often specify a photo or signature size in centimeters — "3.5cm x 4.5cm", "3cm x 1cm" — while every image on your computer is measured in pixels. Getting from one to the other means knowing about DPI, a print-resolution concept most people have never had to think about, and most resizers do not even try to help with.
This tool handles that conversion directly. Pick your unit — pixels, centimeters, millimeters, or inches — type the size a form asks for, and it converts to the exact pixel dimensions for you, using 300 DPI by default (standard print resolution, right for passport photos and signatures) or a DPI you set yourself. Switch units at any point and the size is preserved, not reset.
If you just want to resize by exact pixels or a quick percentage, that still works exactly as before — the unit selector defaults to pixels, and the 25/50/75/100% buttons scale from the original size. An aspect-ratio lock keeps your image proportional automatically, so a width change does not leave you with a stretched result — turn it off if you genuinely need to change width and height independently.
One thing this tool does not do: reduce file size in kilobytes. If a form asks for a photo "under 100KB" rather than a specific width and height, that is a compression job, not a resizing one — the Image Compressor handles that instead, including its own target-KB field.
Everything runs in your browser using the Canvas API — your photo is never uploaded, resized instantly, and there is no account or software involved.
Click the cm unit button, type the width and height a form asks for, and it converts to the right pixel dimensions automatically — 300 DPI by default, which matches standard print and passport-photo requirements.
At the standard 300 DPI used for passport photos, 3.5cm x 4.5cm works out to about 413 x 531 pixels. Select cm as the unit here and type 3.5 and 4.5 directly rather than doing the math yourself.
300 is the standard for print and passport-style photos, which is why it is the default. Use 96 if you are sizing something for on-screen or web use instead, where DPI does not really apply, or whatever specific DPI a form explicitly requests.
Your size is preserved as pixels underneath — switching from cm to inches (or back) just re-displays the same physical size in the new unit, so you do not lose your work by picking the wrong unit first.
Not unless you turn off the aspect-ratio lock — with it on, width and height scale together.
Yes, though enlarging beyond the original resolution will look softer since no new detail is created.
No — that is a file-size job, not a dimension one. Use the Image Compressor instead, which has its own target-KB field built for exactly that.
Yes — the same cm, mm, or inch conversion works for any image, including a scanned or photographed signature that a form specifies in centimeters.
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Drop an image here, or click to browse
Resize by exact pixels, cm, mm, or inches — entirely in your browser