SajinbaroCropping and aspect ratios: 1:1, 4:3 and 16:9
What an aspect ratio is, common ratios, how much of a phone photo is left after cropping to 1:1 or 16:9, and when to crop, resize or add a margin instead.
Reviewed: 2026-10-07 · Sources checked: 2026-10-07
How do I make a photo 1:1 or 16:9?
An aspect ratio is width compared with height. If your photo's ratio differs from the one you need, you either cut off the edges to fill the frame (crop) or keep the whole photo and fill the extra space with a margin (product image sizing). Resizing alone cannot change the ratio without stretching the picture.
1. What an aspect ratio is
The ratio is width ÷ height. A 4032×3024 photo is 4032 ÷ 3024 = 1.33…, written as 4:3. Images with different pixel counts but the same ratio have the same shape: 1600×1200 and 800×600 are both 4:3.
| Ratio | Shape | Often used for (examples) |
|---|---|---|
| 1:1 | Square | Profile pictures, product main images |
| 4:3 | Slightly wide | The default photo on many phone cameras |
| 3:2 | Landscape | Many digital cameras |
| 16:9 | Wide | Video thumbnails, widescreen displays |
| 3:4 · 9:16 | Portrait | Upright photos, vertical screens |
The uses are common examples only — check the exact requirements of the site you are uploading to.
2. Cropping a 4:3 phone photo to other ratios
Changing the ratio cuts off part of the longer side. When you pick a ratio in Sajinbaro's crop tool, it selects the largest centred area at that ratio. For a 4032×3024 photo:
| Ratio | Size kept (px) | Starts at | Area kept |
|---|---|---|---|
| 1:1 | 3024×3024 | X 504, Y 0 | about 75% |
| 16:9 | 4032×2268 | X 0, Y 378 | about 75% |
| 3:4 | 2268×3024 | X 882, Y 0 | about 56.3% |
16:9 removes the top and bottom; 1:1 and 3:4 remove the sides. If something important is cut off, drag the area to move it.
3. Crop, resize or add a margin?
| Method | Ratio | What is lost | Use it when |
|---|---|---|---|
| Crop | Changes to the target | The edges | You want to remove background and fill the frame |
| Resize | Unchanged | Nothing (fewer pixels) | The ratio is right and only the size must shrink |
| Add margin (product image) | Changes to the target | Nothing (extra space is background) | Nothing of the product may be cut off |
If a requirement fixes both size and ratio, such as 1000×1000, the cleanest order is: crop or add a margin to get the ratio, then resize, then check the file size.
Sources and rules
- Calculation: The size examples in this guide are generated by the same code as the tools on this site.
- Ratio calculation: Ratio = width in px ÷ height in px. The table in section 2 uses the same code as Sajinbaro's crop tool.
- CSS aspect-ratio (MDN): How a width-to-height ratio is expressed as width / height (checked 2026-10-07).