How to Resize an Image to Exact Pixel Dimensions Without Stretching It
· 6 min read
A form, a website or a printer asks for an image of exactly 200 × 230 pixels. You type both numbers into a resizer, and either the face looks wider than it should or one side comes out shorter than you asked for. Both happen for the same reason. This guide explains it, with the numbers, and shows how to get the exact size without distortion.
The quick answer
- Compare shapes. Divide the width by the height for the size you need and for your image. If the two numbers are close, go to step 2. If not, crop the image to the right shape first (see below).
- Open the Image Resizer, add the image and choose Pixels under Resize by.
- Enter the width and the height, and leave Keep aspect ratio switched on.
- Check the new size shown in the list, press Resize images and download the file. It is named after the original with the new size added, for example
photo-200x230.jpg.
The image is resized by your browser on your own device and is never uploaded.
What aspect ratio is
The aspect ratio is the width divided by the height. It describes the shape of an image, whatever its size:
| Size in pixels | Width ÷ height | Shape |
|---|---|---|
| 4000 × 3000 | 1.33 | Landscape phone photo (4:3) |
| 3000 × 4000 | 0.75 | Portrait phone photo (3:4) |
| 200 × 230 | 0.87 | A typical form photo box |
| 1080 × 1080 | 1.00 | Square |
When the shape of your image and the shape of the box differ, something has to give. There are only three options: the image fits inside the box and one side comes out shorter, the image is stretched to fill the box, or part of the image is cut away. The resizer does the first two. Cutting away (cropping) is a separate step that you do first.
What the resizer does with your numbers
Here is what happens to a 3000 × 4000 portrait photo with different settings:
| You enter | Keep aspect ratio | Result |
|---|---|---|
| Width 600, height empty | not needed | 600 × 800 |
| Height 230, width empty | not needed | 173 × 230 |
| Width 200 and height 230 | On | 173 × 230: it fits inside the box |
| Width 200 and height 230 | Off | 200 × 230, stretched sideways by about 16% |
| 50% | not needed | 1500 × 2000 |
Leaving one box empty is the simplest way to keep the shape: the other side is worked out from the image's own proportions. Filling in both boxes with Keep aspect ratio on makes each image fit inside that box, so the height reaches 230 while the width stops at 173.
Switching Keep aspect ratio off forces the exact size. For a 0.75 photo squeezed into a 0.87 box, every face becomes about 16% wider. On a passport-style photo that is easy to notice.
Cropping to the right shape first
To get exactly 200 × 230 without stretching, cut the photo to the same 200 : 230 shape, then resize.
For a 3000 × 4000 photo, keep the full width of 3000 pixels and work out the height that matches: 3000 × 230 ÷ 200 = 3450. So you trim 550 pixels from the height, for example some from above the head and the rest from below the shoulders. A 3000 × 3450 image resized with width 200 and height 230 comes out at exactly 200 × 230, with nothing stretched.
You can crop with the crop option in your phone's photo editor. If you would rather do it in the browser, the Passport-Size Photo Maker has a Custom millimetres size that crops to any shape: enter 20 × 23 mm for a 200 × 230 pixel box, drag the crop box into place and press Download one JPG. You get a 236 × 272 pixel image in the right shape, which you then resize to 200 × 230.
Why your image did not get bigger
Do not enlarge smaller images is switched on by default. Images that are already smaller than the size you entered keep their size, because enlarging cannot add detail that was never there. It spreads the existing pixels over a bigger area, so enlarged photos look soft.
Switch it off only when a form insists on a minimum size and you have nothing larger. A better fix is to go back to the original photo from your camera instead of a copy someone forwarded to you, which may already have been made smaller.
Quality, format and file size
Making an image smaller in pixels also makes the file smaller. Halving the width and height leaves a quarter of the pixels.
- JPG and WebP are saved at the Quality you choose. The default of 90% keeps photos sharp; the tool suggests 85 to 92% for sensible file sizes.
- PNG is lossless, so the quality setting does not apply, and a photo saved as PNG is usually several times larger than the same photo as JPG.
- GIF and BMP images are saved as PNG when you keep the original format.
If the form also has a KB limit, choose JPG and lower the quality a little, or resize first and then use the Image Compressor to reach the limit.
Resizing a batch to one width
The same settings apply to every image you add, up to 20 at a time. That makes the width-only method useful for product photos, a photo album or images for a blog: type 1200 in Width, leave Height empty, and every image becomes 1200 pixels wide while keeping its own shape. A landscape photo and a portrait photo come out with different heights, and neither is distorted. You can download them one by one or together as a ZIP file.
Mistakes to avoid
- Switching off Keep aspect ratio to force a size. It works on the numbers and ruins the picture. Crop first instead.
- Resizing a resized copy. Each round of resizing and saving loses a little detail. Keep the original and resize from it every time.
- Adding an iPhone HEIC photo. The resizer does not accept HEIC or AVIF files. Convert them to JPG first with the Image Converter.
- Expecting animation to survive. An animated GIF or WebP is resized as a still image of its first frame.
Frequently asked questions
The form gives the size in centimetres, not pixels. What do I enter?
An image file has only pixels; its size in centimetres depends on the DPI used when it is printed. Pixels = centimetres ÷ 2.54 × DPI, so 3.5 cm at 300 DPI is about 413 pixels. If the notice states a DPI, use it in that formula. For the common 35 × 45 mm photo, the Passport-Size Photo Maker produces a 300 DPI JPG directly.
Does resizing remove the location from my photo?
Yes. Resized images are saved without EXIF data, so the camera model, date and GPS location are not copied. Photos are turned upright first, so they display the right way round everywhere.
Can I resize on my phone?
Yes, in the browser. Phones and tablets can create images up to about 16.7 megapixels, for example 4096 × 4096, and the list marks anything larger as "Too large" before you start.
Wrapping up
An exact size without stretching is a matter of shape: if your image and the box have the same width-to-height ratio, the Image Resizer gets it right with Keep aspect ratio on. If they differ, crop to the right shape first, then resize. Keep the original, so you can start again if a form changes its rules.