Aspect Ratio Calculator

Last updated: May 202614,800 searches/monthDisplay & Monitor

An aspect ratio is the proportional relationship between a screen’s width and height, expressed as two numbers (e.g., 16:9). Enter any pixel dimensions to instantly find the simplified ratio, see if it matches a standard format like 4:3 or 21:9, or scale to a new size without distortion. Used for monitors, video exports, social media crops, and print design.

Width (px)

Height (px)

Common Aspect Ratios

Click any ratio to scale it

How to Use This Calculator

Calculate Ratio

Enter your width and height in pixels. The calculator reduces them using GCD to give you the simplest ratio — and tells you if it matches a standard format like 16:9.

Scale Dimensions

Switch to Scale Dimensions and enter an aspect ratio plus one known side. The calculator solves for the missing dimension — great for resizing images or planning screen layouts.

Quick Ratios

Click any card in the Common Aspect Ratios grid to instantly load that ratio into the scale tool. Useful for quickly checking what 2560px wide at 21:9 would be in height.

Common Aspect Ratios: Complete Reference Table

The table below covers every major aspect ratio used in monitors, video, photography, and social media — with typical resolutions and use cases for each.

Ratio	Decimal	Common Resolutions	Used For
16:9	1.78	1280×720, 1920×1080, 2560×1440, 3840×2160	PC monitors, TVs, YouTube, streaming — most common today
21:9	2.33	2560×1080, 3440×1440, 5120×2160	Ultra-wide gaming monitors, cinematic films
32:9	3.56	3840×1080, 5120×1440	Super ultra-wide monitors, dual-screen replacement
16:10	1.60	1920×1200, 2560×1600, 3840×2400	MacBooks, professional displays, extra vertical space
4:3	1.33	800×600, 1024×768, 1600×1200	Legacy CRT monitors, older software, some photography
5:4	1.25	1280×1024	Older LCD monitors, certain professional workstations
1:1	1.00	Any square (e.g. 1080×1080)	Instagram feed, profile pictures, album art
9:16	0.56	1080×1920, 1080×2400	Reels, TikTok, Shorts, phone wallpapers (vertical video)
4:5	0.80	1080×1350	Instagram portrait posts — maximum feed real estate
3:2	1.50	Various (e.g. 3000×2000)	35mm film / DSLR / mirrorless camera sensors
2:1	2.00	2560×1280, 4000×2000	Panoramic photography, some smartphone displays

16:9 accounts for over 80% of desktop monitors sold worldwide as of 2024. Ultra-wide (21:9) adoption has grown to ~8% of gaming monitors.

Frequently Asked Questions

What is an aspect ratio?

An aspect ratio is the proportional relationship between a display's width and height, expressed as two numbers separated by a colon — for example 16:9. It describes the shape of the image or screen without specifying the actual pixel dimensions. A 1920×1080 monitor and a 1280×720 monitor both have a 16:9 aspect ratio.

What is the most common aspect ratio for monitors?

16:9 is by far the most common aspect ratio today, used in the majority of computer monitors, laptops, TVs, and video content. It replaced the older 4:3 ratio (used on CRT TVs and early LCD monitors) around 2010. Ultra-wide monitors use 21:9, and some creative professionals use 16:10 (common on MacBooks and professional displays).

What aspect ratio should I use for YouTube videos?

YouTube's standard and recommended aspect ratio is 16:9, corresponding to resolutions like 1920×1080 (Full HD), 2560×1440 (2K), or 3840×2160 (4K). Shorts use a vertical 9:16 ratio. Uploading a video with a different aspect ratio causes YouTube to add black bars (letterboxing) to fill the frame.

How do I calculate the aspect ratio of an image?

Divide both the width and height by their Greatest Common Divisor (GCD). For example, 1920×1080: GCD(1920, 1080) = 120, so 1920÷120 = 16 and 1080÷120 = 9, giving 16:9. Our calculator does this automatically — just enter the width and height.

How do I scale a resolution while keeping the same aspect ratio?

Use the Scale Dimensions tab. Enter the aspect ratio (e.g., 16 and 9) and the width or height you want, and the calculator solves for the missing dimension. For example, with a 16:9 ratio and a known width of 1280px, the required height is 1280÷16×9 = 720px.

What is the difference between 16:9 and 16:10?

16:10 (also written 8:5) is slightly taller than 16:9 — it provides about 11% more vertical screen space. It was popular on professional monitors and laptops in the mid-2000s, and has made a comeback on modern MacBooks and some premium displays. The extra height is useful for productivity tasks like reading documents and coding.

What is the aspect ratio of 4K resolution?

Standard 4K (3840×2160, also called 4K UHD) has a 16:9 aspect ratio — the same shape as 1080p and 1440p. Cinema 4K (DCI 4K: 4096×2160) has a slightly wider ratio of approximately 256:135 (~1.90:1), which is close to 2:1. When people refer to '4K' in consumer devices — TVs, monitors, phones — they almost always mean 3840×2160 at 16:9.

What is the best aspect ratio for gaming monitors?

For most games and competitive play, 16:9 at 1080p, 1440p, or 4K is the standard. It offers the widest game compatibility and the highest refresh rates (up to 480 Hz on some 1080p panels). Ultra-wide 21:9 (3440×1440) provides more peripheral vision in open-world and racing games, but some competitive shooters restrict the field of view for fairness. Super ultra-wide 32:9 is niche — great for simulation games but often unsupported in competitive titles.

Last updated: May 2026