How to use it
- Type the width and height in centimetres.
- Choose the DPI (300 for print and most forms).
- Choose your photo, check the fit mode and download the result.
How centimetres turn into pixels
A picture is made of pixels, and centimetres only matter when it is printed. To resize an image to a size in cm you need a DPI (dots per inch). The formula is: pixels = cm ÷ 2.54 × DPI. At 300 DPI, 1 cm is about 118 pixels.
Common sizes at 300 DPI: 3.5 × 4.5 cm is 413 × 531 pixels (passport photos), 5 × 5 cm is 591 × 591 pixels, 10 × 15 cm (4 × 6 in) is 1181 × 1772 pixels, and 15 × 20 cm is 1772 × 2362 pixels. At 72 DPI the same sizes are much smaller.
Use "Crop to fill" to keep the frame full and trim the edges, "Fit inside" to keep the whole photo with white bars, or "Stretch" to force the exact size. For passport photos, check the rules in our size guide in cm, inches and pixels.
If a site asks for a file size such as 50KB or 100KB, resize first and then use the compress tool. For exact pixel sizes, use the pixel resize tool.
Questions
How do I resize an image to a size in centimetres?
Type the width and height in cm, choose the DPI (300 for print), and the pixel size is worked out for you. Then choose your photo and download the result.
How many pixels is 1 cm?
It depends on the DPI. At 300 DPI, 1 cm is about 118 pixels. At 150 DPI it is about 59 pixels, and at 72 DPI about 28 pixels.
What is 3.5 × 4.5 cm in pixels?
At 300 DPI, 3.5 × 4.5 cm is 413 × 531 pixels. This is the common 35 × 45 mm passport photo size.
What is 2 × 2 inches in pixels?
At 300 DPI, 2 × 2 inches is 600 × 600 pixels.
Which DPI should I choose?
Use 300 DPI for printing and for forms that ask for a size in cm or mm. Use 72 DPI only when the size is for a screen. If a form asks for pixels directly, use the <a href="/resize-image/">pixel resize tool</a>.
Does the file get the DPI value too?
This tool sets the pixel size from your cm size and DPI. If a form also checks the DPI stored in the file, use the <a href="/change-image-dpi/">DPI tool</a> afterwards.
Is my image uploaded?
No. Resizing happens in your browser and nothing is sent to a server.