KB vs pixels vs cm: what the form is actually asking for

Forms often list three different numbers. They measure different things, and you usually have to meet all of them.

KB: file size

KB is how much storage the file takes. Portals limit it to keep uploads small. You change it with JPEG quality, and the resizer does that for you. Some portals count 1 KB as 1000 bytes and others as 1024, so we stay inside both.

Pixels: dimensions

Pixels are the width and height of the image, like 200 × 230. If the form gives pixels, enter them exactly.

cm or inches: printed size

“3.5 × 4.5 cm” describes the photo as it would be printed. To turn it into pixels, multiply by the DPI. At 300 DPI, 3.5 × 4.5 cm is 413 × 531 px. Use the cm to pixels converter.

DPI

DPI only links pixels to physical size. Most portals don’t read it, so meet the pixel and KB limits and you’re done.