# Aspect Ratio Calculator – 16:9, 4:5, 9:16 & Social Media Sizes

> Free aspect ratio calculator. Find the ratio of any size, like 1920×1080, or get the missing width or height for 16:9, 4:5, 9:16 and more. Social sizes included.

Canonical: https://scheduleforyou.com/tools/aspect-ratio-calculator

Type a width and height to get the aspect ratio, or pick a ratio and one side to get the other. A table of recommended social media image sizes is built in.

This page has an aspect ratio calculator that runs in the browser; use the HTML page to run it. The text below is the guide that goes with it.

## How to use this aspect ratio calculator
This aspect ratio calculator works both ways. **Find the ratio** turns a width and height into an aspect ratio, such as 1920 × 1080 into 16:9. **Calculate a size** does the reverse: pick a ratio, type the side you know, and it fills in the other in whole pixels. Below both modes sits a table of recommended sizes for Instagram, TikTok, YouTube, X, LinkedIn, Facebook, Pinterest and Threads.

### Find the ratio
Choose **Find the ratio** and enter a **Width (px)** and **Height (px)**. You get four answers:

- **Aspect ratio**: the size reduced to its simplest whole-number form, such as 16:9 or 4:5.
- **Decimal**: width ÷ height, rounded to three places. 1.778 is 16:9, 0.8 is 4:5.
- **Closest common ratio**: the nearest well-known ratio and what it's usually used for, with **matches** if it's within 1%, or how far off it is, for example "2.4% off".
- **Orientation**: Landscape, Portrait or Square.

**Swap ⇄** flips width and height, which turns a landscape size into its portrait version.

### Calculate a size
Choose **Calculate a size** and pick a ratio: 1:1, 4:5, 3:4, 2:3, 9:16, 16:9, 1.91:1, 4:3 or 21:9. For anything else, choose **Custom** and type a ratio such as 2.35:1, 16/9, 16x9 or just 1.91. Enter the side you know in the field marked **Locked**, and the **Calculated** field shows the other one. Press **🔒 ⇄** to lock the height instead of the width. The copy button copies the size as text, for example "1080x1350", ready to paste into an export dialog.

### Rounding to whole pixels
Images can't have half pixels, so results are rounded. When rounding was needed, a note gives the exact value. A 16:9 image 1080 pixels wide comes out as 1080 × 608, with the note "exactly 607.5 px".

## What aspect ratio is 1920x1080?
1920 × 1080 is 16:9. Both numbers divide by 120, which leaves 16 and 9; as a decimal, 1920 ÷ 1080 = 1.778. It's the standard widescreen shape for Full HD video, YouTube and most TV and laptop screens.

### Other sizes people ask about
| Size | Aspect ratio | Closest common ratio |
|---|---|---|
| 1280 × 720 | 16:9 | 16:9, widescreen video |
| 3840 × 2160 | 16:9 | 16:9, widescreen video |
| 1080 × 1920 | 9:16 | 9:16, vertical video and Stories |
| 1080 × 1350 | 4:5 | 4:5, portrait feed post |
| 1080 × 1440 | 3:4 | 3:4, portrait |
| 4032 × 3024 (a typical phone photo) | 4:3 | 4:3, classic screen |
| 6000 × 4000 | 3:2 | 3:2, camera photo |
| 1280 × 800 | 8:5 | 16:10, laptop screen |
| 3440 × 1440 | 43:18 | About 21:9, ultrawide (2.4% off) |

### Why some sizes give odd ratios
Some sizes don't reduce to small numbers. 1366 × 768, a common laptop resolution, simplifies to 683:384. The calculator still shows it as **≈ 16:9 · matches**, because it's within 1% of 16:9. The same happens with 1080 × 566 (540:283), which is 1.91:1 for practical purposes.

## 16:9 calculator: common 16:9 sizes
To get the height of a 16:9 image, multiply the width by 9 and divide by 16. To get the width, multiply the height by 16 and divide by 9. In **Calculate a size**, pick 16:9 and type either side.

| Width | Height |
|---|---|
| 1280 | 720 |
| 1600 | 900 |
| 1920 | 1080 |
| 2560 | 1440 |
| 3840 | 2160 |

### The formula for any ratio
For a ratio W:H, the new height is your width × H ÷ W, and the new width is your height × W ÷ H. That's all the calculator does, plus the rounding. Resizing to a different ratio always means cropping or adding borders; keeping the same ratio means the picture scales without distortion.

## 4:5 and 9:16 sizes for social media
### 4:5: the tallest feed post
4:5 is the portrait shape for Instagram, Facebook and Threads feed posts. At 1080 pixels wide it's 1080 × 1350. At the time of writing, Instagram's publishing API, which scheduling tools use, accepts feed images between 4:5 and 1.91:1, so 4:5 is the tallest shape that's safe everywhere, and it takes up the most screen space. Our guide to [Instagram aspect ratios and cropping](https://scheduleforyou.com/blog/instagram-aspect-ratio-cropping) explains the range in detail.

### 9:16: full-screen vertical
9:16 is the full-screen phone shape for TikTok videos, Instagram Stories and Reels, and YouTube Shorts: 1080 × 1920 at the usual resolution. Keep text and faces away from the top and bottom edges, where each app places buttons and captions. See [TikTok video size and ratio](https://scheduleforyou.com/blog/tiktok-video-size-ratio) for more.

### 1.91:1: link previews and landscape posts
1.91:1 is the wide shape used for link previews and landscape posts on Facebook, LinkedIn and Instagram. Because 1.91 is itself a rounded number, sizes such as 1080 × 566, 1200 × 627 and 1200 × 630 all count as 1.91:1. In **Calculate a size**, 1.91:1 at 1080 wide gives 1080 × 565; either height works.

## Social media image sizes
The calculator's table lists these recommended sizes at the time of writing. Tap a size there to load it into **Find the ratio**.

| Platform | Use | Size (px) | Ratio |
|---|---|---|---|
| Instagram | Feed post, portrait | 1080 × 1350 | 4:5 |
| Instagram | Feed post, square | 1080 × 1080 | 1:1 |
| Instagram | Feed post, landscape | 1080 × 566 | 1.91:1 |
| Instagram | Stories & Reels | 1080 × 1920 | 9:16 |
| TikTok | Video | 1080 × 1920 | 9:16 |
| YouTube | Video | 1920 × 1080 | 16:9 |
| YouTube | Thumbnail | 1280 × 720 | 16:9 |
| YouTube | Shorts | 1080 × 1920 | 9:16 |
| X | Image post | 1600 × 900 | 16:9 |
| LinkedIn | Post | 1200 × 627 | 1.91:1 |
| LinkedIn | Post, square | 1080 × 1080 | 1:1 |
| Facebook | Post, portrait | 1080 × 1350 | 4:5 |
| Facebook | Post, landscape (link) | 1200 × 630 | 1.91:1 |
| Pinterest | Pin | 1000 × 1500 | 2:3 |
| Threads | Post | 1080 × 1350 | 4:5 |

Platforms change their recommendations now and then, so check their help pages if something looks cropped. To change a photo's shape, use the [Instagram photo resizer](https://scheduleforyou.com/tools/instagram-photo-resizer) or the [TikTok photo resizer](https://scheduleforyou.com/tools/tiktok-photo-resizer); to fit several photos into one of these sizes, use the [photo collage maker](https://scheduleforyou.com/tools/photo-collage-maker).

## Frequently asked questions
### How do I calculate an aspect ratio?
Divide the width and height by their greatest common divisor. For 1920 × 1080 that's 120, giving 16:9. Or type both numbers into Find the ratio and the calculator does it for you.

### What is a 16:9 resolution?
Any size where the width is 16/9 of the height: 1280 × 720, 1920 × 1080, 2560 × 1440 and 3840 × 2160 are the common ones.

### What size is 4:5?
At 1080 pixels wide, 4:5 is 1080 × 1350, the portrait size for Instagram, Facebook and Threads feed posts.

### What size is 9:16?
At 1080 pixels wide, 9:16 is 1080 × 1920, the full-screen size for TikTok, Instagram Stories and Reels, and YouTube Shorts.

### Is 1080 × 1080 the same as 1:1?
Yes. Any size with equal width and height is 1:1, a square, and the calculator shows its orientation as Square.

### Can I use decimal ratios like 2.35:1?
Yes. Choose Custom in Calculate a size and type 2.35:1, or just 2.35. At 1920 wide that gives 1920 × 817.

## Schedule posts in the right size everywhere
Once your images are the right shape, Schedule For You publishes them to Instagram, TikTok, YouTube, X, LinkedIn, Facebook, Pinterest, Threads, Bluesky and Google Business Profile from one queue, with a caption tailored for each platform. It posts the files exactly as you upload them and doesn't crop or resize, so size them here first. Plans start at $19/month. [Start your 7-day free trial](https://scheduleforyou.com/signup). A card is required and you aren't charged until day 8.

## Related

- [All free tools](https://scheduleforyou.com/tools)
- [Schedule posts with Schedule For You](https://scheduleforyou.com/)