Cheat Sheet
Aspect Ratio Cheat Sheet
Every common aspect ratio in one place: decimal values, standard resolutions, portrait counterparts, and the formulas to convert dimensions yourself.
By AspectRatioTool Editorial Team
| Updated July 18, 2026
What You Will Find
12 common ratios with decimal values
Standard resolutions for each ratio
Portrait and landscape pairs
Formulas for quick conversions
Quick reference
Common Aspect Ratios at a Glance
The most widely used aspect ratios across video, photography, social media, and displays, sorted by how often you will encounter them.
| Ratio | Shape | Decimal | Orientation | Typical Uses |
|---|---|---|---|---|
| 16:9 | 1.778 | Landscape | YouTube, TV, monitors, presentations | |
| 21:9 | 2.333 | Landscape | Ultrawide monitors, cinematic gaming | |
| 4:3 | 1.333 | Landscape | Classic TV, iPad, presentations | |
| 3:2 | 1.500 | Landscape | DSLR and mirrorless photos, prints | |
| 1:1 | 1.000 | Square | Instagram posts, profile pictures, album covers | |
| 4:5 | 0.800 | Portrait | Instagram portrait posts, vertical feeds | |
| 9:16 | 0.563 | Portrait | TikTok, Reels, Stories, Shorts | |
| 16:10 | 1.600 | Landscape | Laptops, productivity monitors | |
| 32:9 | 3.556 | Landscape | Super ultrawide monitors, sim racing | |
| 2.35:1 | 2.350 | Landscape | Anamorphic films, classic cinema | |
| 2.39:1 | 2.390 | Landscape | Modern films, CinemaScope | |
| 2:3 | 0.667 | Portrait | Portrait photography, 4 x 6 inch prints |
Standard Resolutions by Ratio
The pixel dimensions you will actually export, stream, or buy a screen in, grouped by aspect ratio.
16:9 Open calculator
| Resolution | Name | Megapixels |
|---|---|---|
| 1280 x 720 | HD 720p | 0.9 MP |
| 1920 x 1080 | Full HD 1080p | 2.1 MP |
| 2560 x 1440 | QHD 1440p | 3.7 MP |
| 3840 x 2160 | 4K UHD | 8.3 MP |
| 7680 x 4320 | 8K UHD | 33.2 MP |
16:10 Open calculator
| Resolution | Name | Megapixels |
|---|---|---|
| 1280 x 800 | WXGA | 1.0 MP |
| 1920 x 1200 | WUXGA | 2.3 MP |
| 2560 x 1600 | WQXGA | 4.1 MP |
21:9 Open calculator
| Resolution | Name | Megapixels |
|---|---|---|
| 2560 x 1080 | UW-FHD | 2.8 MP |
| 3440 x 1440 | UW-QHD | 5.0 MP |
| 5120 x 2160 | 5K2K | 11.1 MP |
32:9 Open calculator
| Resolution | Name | Megapixels |
|---|---|---|
| 3840 x 1080 | DFHD | 4.1 MP |
| 5120 x 1440 | DQHD | 7.4 MP |
4:3 Open calculator
| Resolution | Name | Megapixels |
|---|---|---|
| 800 x 600 | SVGA | 0.5 MP |
| 1024 x 768 | XGA | 0.8 MP |
| 1600 x 1200 | UXGA | 1.9 MP |
| 2048 x 1536 | QXGA | 3.1 MP |
3:2 Open calculator
| Resolution | Name | Megapixels |
|---|---|---|
| 2160 x 1440 | FHD+ | 3.1 MP |
| 3000 x 2000 | 3K | 6.0 MP |
| 6000 x 4000 | 24 MP DSLR | 24.0 MP |
1:1
| Resolution | Name | Megapixels |
|---|---|---|
| 1080 x 1080 | Instagram Square | 1.2 MP |
| 2048 x 2048 | Album Cover | 4.2 MP |
4:5 Open calculator
| Resolution | Name | Megapixels |
|---|---|---|
| 1080 x 1350 | Instagram Portrait | 1.5 MP |
9:16 Open calculator
| Resolution | Name | Megapixels |
|---|---|---|
| 720 x 1280 | HD Vertical | 0.9 MP |
| 1080 x 1920 | Full HD Vertical | 2.1 MP |
| 2160 x 3840 | 4K Vertical | 8.3 MP |
Portrait and Landscape Pairs
Swap the two numbers to rotate a format: a 16:9 video becomes 9:16 when filmed vertically.
| Landscape | Decimal | Portrait | Decimal |
|---|---|---|---|
| 16:9 | 1.778 | 9:16 | 0.563 |
| 3:2 | 1.500 | 2:3 | 0.667 |
| 4:3 | 1.333 | 3:4 | 0.750 |
| 5:4 | 1.250 | 4:5 | 0.800 |
| 16:10 | 1.600 | 10:16 | 0.625 |
Quick Formulas
Four formulas that cover almost every aspect ratio task, each with a worked example.
Height from width
height = width x ratio height / ratio width
A 1600 px wide 16:9 image: 1600 x 9 / 16 = 900 px tall.
Width from height
width = height x ratio width / ratio height
A 1080 px tall 4:5 post: 1080 x 4 / 5 = 864 px wide.
Ratio from dimensions
divide width and height by their GCD
1920 and 1080 share a GCD of 120, so 1920 x 1080 simplifies to 16:9.
Decimal value
decimal = width / height
21:9 gives 21 / 9 = 2.333, which makes comparing ratios easier.
Frequently Asked Questions
16:9 is the dominant aspect ratio today. It is the standard for YouTube, television, most monitors, and presentation slides. On mobile platforms its vertical counterpart 9:16 is just as important, since TikTok, Reels, Stories, and Shorts all use it.
1920 x 1080 is 16:9. Divide both numbers by their greatest common divisor, 120: 1920 / 120 = 16 and 1080 / 120 = 9. The same ratio applies to 1280 x 720, 2560 x 1440, and 3840 x 2160.
Divide the first number by the second. For 16:9 that is 16 / 9 = 1.778. Decimals make it easy to compare ratios: anything above 1 is landscape, exactly 1 is square, and below 1 is portrait.
It depends on the placement. Feed posts on Instagram perform best at 4:5 (1080 x 1350), square posts use 1:1 (1080 x 1080), and full-screen vertical video on TikTok, Reels, and Shorts uses 9:16 (1080 x 1920). YouTube videos remain 16:9.
Both are cinematic widescreen ratios and look nearly identical. 2.35:1 was the anamorphic standard until the 1970s, when the specification changed to 2.39:1. Modern films labeled "CinemaScope" or "anamorphic" are usually 2.39:1, though the older name 2.35:1 is still used informally.
Yes. The page is built from plain tables, so printing it from your browser produces a clean reference you can keep at your desk. All values stay accurate regardless of paper size.
Related Tools
Aspect Ratio Calculator Calculate dimensions for any ratio, or find the ratio of any width and height. Aspect Ratio Comparison Overlay two ratios and see exactly how their shapes differ. Visual Aspect Ratio Guide See every common ratio drawn to scale with real-world examples. Aspect Ratio vs Resolution Understand the difference between shape and pixel count. Portrait Aspect Ratio Guide Choose the right vertical format for social media and photography. Screen Resolution Checker Detect your current screen resolution and aspect ratio instantly.