How to resize a photo to exact pixels and a file size limit in KB

Exam registrations, job portals, government applications and membership forms often ask for something like “a photo of 200 × 230 pixels, under 50 KB” or “a signature image of 140 × 60 pixels, 10–20 KB”. A phone photo is thousands of pixels wide and several megabytes, so it is rejected. Meeting both limits takes three steps, in a particular order.

Pixels and kilobytes are different limits

• Dimensions — width × height in pixels — describe the shape and detail of the image.
• File size — in KB or MB — is how much storage the file takes. It depends on the dimensions, but also on the format and the compression quality.

You control dimensions by cropping and resizing, and file size mainly by compression. Do them in that order.

Step 1: crop to the right shape

Work out the shape the form wants. 200 × 230 pixels is slightly taller than wide; a square is 1:1. Resizing a photo of a different shape to those dimensions would stretch the face, so crop first.

In Crop Image, type the target width and height directly into the pixel fields, or a larger size in the same proportion, and drag the selection over the part of the photo you want. Cropping keeps the full-resolution pixels, so nothing is lost yet.

Step 2: resize to the exact dimensions

Open the cropped image in Resize Image and enter the exact width; with the aspect ratio locked, the height follows. Because you cropped to the right shape first, it lands on the required height too. Making an image smaller keeps it sharp; avoid making it larger than the original.

Step 3: compress to the KB limit

Add the resized image to Compress Image. Drag the quality slider and watch the estimated size. Stop as soon as it is under the limit — there is no reward for going far below it, only a worse-looking picture. A small image such as 200 × 230 pixels usually reaches a few tens of kilobytes at a moderate quality setting.

If you reach a quality of about 60 and the file is still too big, check the dimensions again: an image that is larger than required is the usual cause.

When there is a minimum size as well

Some forms set a range, such as 20–50 KB, to stop people uploading tiny, blurry images. If your file is below the minimum, raise the quality. Do not enlarge the image to gain kilobytes; it only makes it softer.

Format

Most forms ask for JPG, and some reject anything else. Photos should be JPG. A scanned signature on white paper is also usually requested as JPG; if the form allows PNG, that keeps the strokes crisp.

DPI usually does not matter

For an upload, only the pixels and file size count. A form that also mentions DPI is usually describing a print size — the photo may be printed on an admit card or ID — and the dimensions it gives already take that into account. If it specifically asks for a DPI value, see what DPI means.

Passport and visa photos

For official photos with fixed physical sizes, such as 35 × 45 mm or 2 × 2 inches, the Passport Photo Maker crops to the exact proportions at print quality. If the application is online, check its pixel and KB limits separately and compress the result as above.

Before you upload

• Check the final file's dimensions and size in your computer's file properties.
• Look at it at 100% — the face should be clear and evenly lit.
• Keep the original photo, so you can redo it if the requirements change.