Aspect Ratios Explained: 16:9, 4:3, 1:1 and How to Change Them
Learn what aspect ratios mean, which ones screens, prints and social apps use, and how to change an image's ratio by cropping or padding, with a free tool.
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Free tool: Aspect Ratio ToolAn aspect ratio describes the shape of an image: its width compared with its height. 16:9 is the wide shape of a TV and most video, 1:1 is a square, and 9:16 is the tall shape of a phone story. Getting the ratio right means your picture fills the space it's shown in, without awkward cropping or black bars. This guide explains the common ratios and how to change one with the free Aspect Ratio Tool.
What the numbers mean
A ratio of 16:9 means that for every 16 units of width there are 9 units of height. It says nothing about size: 1280 × 720 and 3840 × 2160 pixels are both 16:9. To find the height for a given width:
Height = width × (second number ÷ first number)
For a 1920-pixel-wide 16:9 image: 1920 × 9 ÷ 16 = 1080 pixels.
Common aspect ratios
| Ratio | Shape | Common uses | Example size |
|---|---|---|---|
| 1:1 | Square | Profile pictures, square posts | 1080 × 1080 |
| 4:5 | Slightly tall | Portrait social media posts | 1080 × 1350 |
| 4:3 | Classic | Many phone photos, tablets, older screens | 1600 × 1200 |
| 3:2 | Photo | Most camera sensors, 6 × 4 inch prints | 6000 × 4000 |
| 16:9 | Widescreen | Video, YouTube, TVs, slides | 1920 × 1080 |
| 9:16 | Tall | Stories, reels and vertical video | 1080 × 1920 |
Changing the ratio: crop or pad
There are two ways to fit an image to a new ratio:
- Crop cuts away part of the picture. It fills the frame but loses the edges. A 4000 × 3000 (4:3) photo cropped to 16:9 keeps its full width and drops to 4000 × 2250, losing a quarter of its height. Cropped to a square, it becomes 3000 × 3000.
- Pad keeps the whole picture and adds bars of color around it to make up the difference, like the black bars around a film on a TV. It's the better choice when nothing can be cut, such as a group photo or a chart.
Going from wide to tall is where cropping hurts most: turning a 1920 × 1080 landscape image into 9:16 keeps a strip only about 608 pixels wide, under a third of the picture. Padding, or choosing a different photo, is often better.
How to change an aspect ratio with Graph Maker
- Open the Aspect Ratio Tool and upload an image, or paste a direct image link.
- Pick a preset ratio (free, 1:1, 4:3, 3:4, 16:9, 9:16, 3:2 or 2:3) or enter a custom ratio, such as 4:5.
- Position the crop box over the part of the picture you want to keep.
- To pad instead of cutting, turn on Allow crop outside image boundaries and move the box past the edges; the extra space is filled with the background color you choose.
- Choose the output format and download the result.
The image is processed in your browser and isn't uploaded.
Tips
- Start from the largest original so the result stays sharp after cropping.
- Keep the subject away from the edges if the image might be cropped again by the platform, for example into a circle or a thumbnail.
- Match the padding color to the image's edges or the page background so the bars look intentional.
- Check the platform's current recommendations; social apps change their preferred sizes from time to time.
Frequently asked questions
What aspect ratio is 1920 × 1080?
16:9. Divide both numbers by their greatest common factor, 120, and you get 16 × 9.
How do I change an image to 16:9 without cropping?
Pad it: allow the crop box to extend outside the image and choose a background color for the extra space. The whole picture stays visible with bars at the sides or top and bottom.
What's the best aspect ratio for social media?
It depends on where the image appears: square (1:1) and portrait (4:5) work well in feeds, 9:16 suits stories and vertical video, and 16:9 suits video and link previews.