How to crop a photo to an exact size
- Open the photo. The Print size panel is already open, set to centimetres at 300 DPI.
- Type the width and height in cm, mm or inches, or tap a common size such as 2 × 2 in or 3.5 × 4.5 cm. The crop box takes that shape at once.
- Change the DPI if the place you are sending it to asks for one — 200 and 300 are the usual numbers.
- Drag the box onto the part you want and press Crop Picture. The result panel shows the pixels, the DPI written into the file and the size it prints at.
Every route on this site crops in the pixels of your original photo; this one adds the step most croppers leave out — turning centimetres or inches into the right number of pixels, and recording the DPI so the file prints at the size you meant.
Common print sizes at 300 DPI
These are the sizes behind the quick buttons. The pixel numbers are rounded to the nearest whole pixel, which is what the saved file contains.
| Size | At 300 DPI | At 200 DPI |
|---|---|---|
| 2 × 2 in | 600 × 600 px | 400 × 400 px |
| 35 × 45 mm | 413 × 531 px | 276 × 354 px |
| 3.5 × 4.5 cm | 413 × 531 px | 276 × 354 px |
| 6 × 4 in print | 1800 × 1200 px | 1200 × 800 px |
| 7 × 5 in print | 2100 × 1500 px | 1400 × 1000 px |
| A4 (210 × 297 mm) | 2480 × 3508 px | 1654 × 2339 px |
Pixels, DPI and print size — what this mode does differently
A digital photo has only pixels. Its printed size is the pixel count divided by the DPI: 600 pixels at 300 DPI print exactly two inches wide, the width of a 2 × 2 in passport print. Most online croppers let you type pixels and stop there, so a form that asks for “3.5 cm × 4.5 cm at 200 DPI” leaves you doing the sum yourself. Here you type the centimetres, the DPI turns them into pixels, the crop box locks to that shape, and the output is resampled with a high-quality filter to exactly that many pixels.
Upscaling is never silent. If the part you selected has fewer pixels than the size needs, the field turns amber, the panel tells you the DPI your crop can really give, and the crop button asks before it enlarges anything. Nothing is uploaded at any point: the photo is decoded, cropped, resampled and encoded in this browser tab, which is why it also works offline once the page has loaded.
Need a fixed pixel count instead? Crop by pixels opens the exact W, H, X and Y fields. For a whole folder, use batch crop.
Frequently asked questions
How many pixels is 3.5 × 4.5 cm?
It depends on the DPI. At 300 DPI it is 413 × 531 px; at 200 DPI it is 276 × 354 px. The panel shows the pixel size under the fields as you type.
Is the DPI really saved in the file?
Yes. JPG files get it in the JFIF density field (and the EXIF resolution tags if you keep camera details); PNG files get a pHYs chunk. WebP and AVIF have no field print software reads, and the result panel says so.
What if my photo is too small for the size I typed?
You see the DPI your crop can really give — for example “Your crop gives 212 DPI at this size” — with a button to use that instead. Keep the higher DPI and you are asked to confirm the enlargement first.
Can I also keep it under a number of KB?
Yes — fill in Keep under in the File-size limit section. The quality is settled for you and the result shows the KB and quality used. For exam forms, Crop photo for form has the presets ready.
Does changing the DPI change the picture?
Not on its own — DPI only tells a printer how big each pixel is. With a physical size set, the DPI decides how many pixels the file gets, and the crop is scaled to exactly that.