About Aspect Ratio & Screen Resolution Calculator
Professional aspect ratio and display resolution calculator for video editors, streamers, and designers. Simplifies dimensions via GCD, scales width/height proportionally, and simulates letterbox/pillarbox padding on standard displays.
Key Capabilities & Features
- Greatest Common Divisor (GCD) simplified aspect ratio reduction
- Proportional dimension solver for target width or target height
- Letterbox and pillarbox padding simulator with active picture area %
- Display presets for 16:9 Cinema, 9:16 Shorts/Reels, 21:9 Ultrawide, and 4:3 Retro
How to Use Aspect Ratio & Screen Resolution Calculator
Enter Original Dimensions
Input source video or image width and height in pixels.
Inspect Aspect Ratio
Review the simplified ratio (e.g. 16:9, 21:9) and decimal multiplier.
Simulate Display Container
Select a target container to view exact letterbox or pillarbox bars in pixels.
Privacy & In-Browser Execution Guarantee
Resolution and dimensional math executed 100% in local client memory.
Frequently Asked Questions
What causes letterboxing and pillarboxing?
Letterboxing (horizontal black bars at top and bottom) occurs when wide content is displayed in a taller screen. Pillarboxing (vertical black bars on left and right) occurs when narrower content (such as 4:3) is viewed on a 16:9 widescreen display.
What is the aspect ratio of 1920x1080?
1920x1080 simplifies to 16:9 (divided by GCD 120), standard for HDTV, YouTube, and PC monitors.