Free Aspect Ratio Calculator
Calculate exact pixel dimensions from any aspect ratio. Enter your ratio and a known dimension to instantly get the missing value.
Supports all standard ratios like 16:9, 4:3, 21:9, 9:16 and custom ratios. Presets for 480p, 720p, 1080p, 4K, and 8K.
Editing is a pain in the ass, right?
That's why we're building Cubix. No more editing hell.
AI Video Editor
Drop your footage, tell it what you want. Cubix cuts, captions, color grades, and exports — fully on its own. No timeline. No manual work. Just results.
Cinematic Screen Recorder
Hit record on Windows. Auto-zoom, cinematic backgrounds, and studio-quality audio kick in automatically — your screen recording looks edited before you've touched a thing.
All Aspect Ratios
16:9, 4:3, 21:9, 9:16, 1:1 and any custom ratio. Pixel-perfect results rounded to even numbers for codec compatibility.
Resolution Presets
Quick presets for 480p, 720p, 1080p, 1440p, 2K, 4K, and 8K. Or enter any custom pixel value.
Instant Results
Get your dimensions instantly with simplified ratio output. Copy the resolution with one click.
Frequently Asked Questions
What is an aspect ratio?
An aspect ratio is the proportional relationship between a video's width and height, expressed as W:H. 16:9 is the standard widescreen ratio used by most TVs, YouTube, and modern cameras.
Why are dimensions rounded to even numbers?
Most video codecs (H.264, H.265) require both width and height to be divisible by 2. Our calculator automatically rounds to the nearest even number for compatibility.
What is the difference between 16:9 and 21:9?
16:9 is standard widescreen (1920×1080), while 21:9 (ultrawide) is used in cinema and ultrawide monitors. True 21:9 at 1080p gives 2520×1080.
What resolution is 16:9 at 1080p?
1080p typically refers to 1920×1080 pixels — the standard 16:9 HD resolution. If you know height (1080px), multiply by 16/9 to get width (~1920px).
Related video calculators
Bitrate, file size, frame rate, and compression — built for creators and developers.