Image cm to Pixel Converter
Find how many pixels a size in cm, mm or inches needs at any DPI, or how big a picture prints. Then make a photo of exactly that size.
Free, no sign-up. Everything runs in your browser.
3.5 x 4.5 cm at 300 DPI =
413 x 531 pixels
| DPI | 3.5 x 4.5 cm in pixels |
|---|---|
| 72 | 99 x 128 |
| 96 | 132 x 170 |
| 150 | 207 x 266 |
| 200 | 276 x 354 |
| 300 | 413 x 531 |
| 600 | 827 x 1063 |
Step by step
How to use Image cm to Pixel Converter
- 1
Type the size
Enter the width and height in cm, mm or inches, or pick a common size such as a passport photo.
- 2
Choose the DPI
300 for printing, or the DPI your form asks for. The pixels are shown at once, with a table for other DPIs.
- 3
Or go the other way
Switch to Pixels to cm to see how big a picture of a known pixel size prints.
- 4
Make the photo
Optional: add a photo, crop it in the frame and download a JPG of exactly that many pixels, set to that DPI.
Overview
About Image cm to Pixel Converter
A size in cm only becomes a number of pixels once you know the DPI (dots per inch). The rule is simple: pixels = size in inches x DPI, and 1 inch = 2.54 cm. So 3.5 cm at 300 DPI is 3.5 / 2.54 x 300 = 413 pixels. This tool does the sum for width and height together, for cm, mm and inches, and rounds to whole pixels like image editors do.
It also works backwards: give it a picture's width and height in pixels and a DPI, and it shows how many cm, mm and inches it will print. A table under the answer shows the same size at 72, 96, 150, 200, 300 and 600 DPI, so you can see what a form or a printer will expect.
If you need the picture itself, add a photo below the answer. It is shown in a frame with the exact shape of your size; move and zoom it, and download a JPG of exactly the pixel size shown, with the DPI written into the file so it prints at the right size.
Everything runs in your browser. Your photo is not uploaded.
When it helps
- Working out the pixel size of a 3.5 x 4.5 cm passport photo, a 2.5 x 3.5 cm PAN photo or a stamp size photo
- Online forms that give the photo size in cm while your phone shows pixels
- Checking how big a picture will print before sending it to a print shop
- Making a photo of an exact size in cm, ready to print at the right DPI
Specs
Supported files and limits
- Units
- cm, mm and inches to pixels, and pixels back to all three
- DPI
- 72, 96, 150, 200, 300, 600, or any whole number
- Rounding
- To the nearest whole pixel, at least 1
- Photo output
- JPG of the exact pixel size with the DPI set, from JPG, PNG or WebP up to 30 MB; up to 16 megapixels
- Where it runs
- In your browser. Nothing is uploaded.
Common sizes in pixels
Pixels = size in inches x DPI, rounded. 1 inch = 2.54 cm.
| Size | 96 DPI (screen) | 200 DPI | 300 DPI (print) |
|---|---|---|---|
| 1 cm | 38 px | 79 px | 118 px |
| 1 inch | 96 px | 200 px | 300 px |
| 3.5 x 4.5 cm (passport photo) | 132 x 170 px | 276 x 354 px | 413 x 531 px |
| 2.5 x 3.5 cm (PAN card photo) | 94 x 132 px | 197 x 276 px | 295 x 413 px |
| 2 x 2.5 cm (stamp size) | 76 x 94 px | 157 x 197 px | 236 x 295 px |
| 2 x 2 inch | 192 x 192 px | 400 x 400 px | 600 x 600 px |
| A4 (21 x 29.7 cm) | 794 x 1123 px | 1654 x 2339 px | 2480 x 3508 px |
Good to know
- Pixels for a size in cm depend on the DPI. If a form gives only a size in cm, it usually means a printed size; if it gives pixels, use those numbers directly.
- The photo maker crops and resizes. A small photo made bigger in pixels does not gain detail.
- It does not limit the file size in KB. For a KB limit, use Resize & Compress Image to 100KB or the Exam Photo Resizer after this.
- HEIC photos from iPhones are not supported. Share or save them as JPG first.
Fix a problem
Troubleshooting
My result is one pixel different from another site
Sites round differently. This tool rounds to the nearest whole pixel; if a form gives an exact pixel size, use that instead.
The photo option says the size is too big
Very large sizes at high DPI (for example A4 at 600 DPI) are too big for a browser. Choose 300 DPI or a smaller size.
The printed photo is the wrong size
Print at Actual size or 100%, not Fit to page. The JPG carries the DPI, so the printer knows its size.
The form says the file is too large
Run the downloaded JPG through Resize & Compress Image to 100KB with the KB limit the form gives.
FAQ
Frequently asked questions
How many pixels is 1 cm?
It depends on the DPI: about 38 pixels at 96 DPI, 79 at 200 DPI and 118 at 300 DPI.
What is 3.5 x 4.5 cm in pixels?
413 x 531 pixels at 300 DPI, 276 x 354 at 200 DPI, and 132 x 170 at 96 DPI.
How do I convert cm to pixels?
Divide the cm by 2.54 to get inches, then multiply by the DPI. For 5 cm at 300 DPI: 5 / 2.54 x 300 = 591 pixels.
How do I convert pixels to cm?
Divide the pixels by the DPI to get inches, then multiply by 2.54. For 600 pixels at 300 DPI: 600 / 300 x 2.54 = 5.08 cm.
Which DPI should I use?
300 for printing photos and documents. 96 is the usual screen DPI on Windows. If a form names a DPI, use that one.
What is the A4 size in pixels?
2480 x 3508 pixels at 300 DPI, and 1654 x 2339 at 200 DPI.
Can I resize my photo to a size in cm here?
Yes. Type the size and DPI, add the photo below the answer, fit it in the frame and download a JPG of exactly that size.
Is my photo uploaded?
No. The photo is cropped and saved in your browser and never leaves your device.
Is it free?
Yes, free with no sign-up and no watermark.
Keep going
What to do next
- Only need to change the DPI of a picture, without resizing it? Use Change Image DPI. Open Change Image DPI
- Need the photo under a KB limit too? Use Resize & Compress Image to 100KB. Open Resize Image Under 100KB
- Making a passport photo? The Passport Size Photo Maker adds a face guide and print sheets. Open Passport Size Photo Maker
Explore