Free tool
Aspect Ratio Calculator
Type a width and a height to get the ratio, so 1920 x 1080 becomes 16:9 and 1080 x 1350 becomes 4:5, or pick a ratio and one side to get the other. Then see which social formats take that shape.
Last updated: 2026-10-25
An aspect ratio is a width and a height divided by their largest common factor: 1920 x 1080 reduces to 16:9, and 1080 x 1350 to 4:5. The calculator does that for any size, and works the other way too. Give it a ratio and one side and it returns the other side rounded to a whole pixel, so 9:16 at 1920 tall is 1080 x 1920, and it tells you when rounding was needed.
The standard ratios it compares against are the ones the platforms recommend in our spec tables, and only those: 9:16 for Reels, Stories, TikTok, Shorts and video Pins, 2:3 for a standard Pin, 4:5 for Instagram and Threads feed images, 1:1 for a LinkedIn multi image post, 16:9 for YouTube, X posts and LinkedIn video, and 1.91:1 for Facebook feed images and LinkedIn post images.
For any size you enter, it names the closest standard ratio and how far off you are in percent, then lists every format whose accepted range includes your shape, even where it is not the recommended one. A 16:9 landscape video, for example, is accepted as a TikTok video even though TikTok recommends 9:16. Everything is calculated in your browser.
Aspect ratio
4:5
0.800 to 1
4:5 is a standard social ratio.
Used for
- Instagram Feed image
- Instagram Carousel
- Facebook Feed video
- Threads Post image
- Threads Carousel
Formats that accept this shape
- Instagram Feed image
- Instagram Reel
- Instagram Story
- Instagram Carousel
- Facebook Feed image
- Facebook Feed video
- Facebook Reel
- Facebook Story
- Threads Post image
- Threads Post video
- Threads Carousel
- LinkedIn Post image
- LinkedIn Native video
- LinkedIn Multi image post
- X Post image
- X Post video
- TikTok Video post
- TikTok Photo post
- YouTube Short
- YouTube Standard video
- Pinterest Standard Pin
- Pinterest Video Pin
Resize at the same ratio
Type a new width or height and the other side follows.
Standard social ratios
Click one to fill it in.
Platform limits checked on 2026-07-31
Tips
- Pick the ratio before the resolution. Once the shape is right, getting to the recommended size is one step: 4:5 at 1080 wide is 1080 x 1350.
- Keep video dimensions even. Most video encoders want an even width and height, so if a scaled side comes out odd, move it by one pixel.
- Look at the distance, not only the nearest ratio. 1080 x 1920 is exactly 9:16, while 1080 x 1900 is close but not equal, and the platform makes up the difference with a crop or bars.
Frequently asked questions
How do I calculate an aspect ratio?
Divide the width and the height by their greatest common divisor. For 1920 x 1080 that divisor is 120, which gives 16:9. For 1080 x 1350 it is 270, which gives 4:5. The calculator does this for you as you type.
How do I find the height for a given width?
Multiply the width by the ratio's height and divide by the ratio's width. For 4:5 at 1080 wide that is 1080 x 5 / 4, which is 1350. The calculator rounds to a whole pixel and says when it had to.
What aspect ratio is best for social media?
There is no single answer. 9:16 is recommended for full screen video such as Reels, Stories, TikTok and Shorts, 4:5 for Instagram and Threads feed images, 2:3 for standard Pins and 16:9 for YouTube and X. Pick the ratio for the surface you are posting to first.
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