Developer Tools
Aspect Ratio Calculator
Aspect Ratio — aspect Ratio Calculator reduces the width:height ratio by their greatest common divisor, and solves for a missing side at a fixed aspect ratio. This page runs that same calculation on your numbers, in your browser: no signup, no uploads, nothing stored.
Want to work out an aspect ratio? Aspect Ratio Calculator does it from your width, height and new width and shows the simplified ratio and resized dimension clearly, with everything calculated in your browser.
Browser-side developer and utility helpers for everyday and learning use. Everything runs locally in your browser and nothing you enter is uploaded. Validate production or security-critical output with trusted, official tools before relying on it.
About this tool
Aspect Ratio Calculator reduces the width:height ratio by their greatest common divisor, and solves for a missing side at a fixed aspect ratio. It matters when a format, encoding or size has to be exactly right for the system reading it. Here is the calculation on real numbers: A 1920 × 1080 image simplifies by dividing both by 120: 1920:1080 = 16:9 . For your own figures, use the calculator above — same method, your inputs, computed on-device.
How to use
- Enter the original width.
- Enter the original height.
- Optionally enter a new width to scale to.
- Run the calculator to read the ratio.
Why use the Aspect Ratio Calculator
Instant
Each result is computed on your device the moment you run the tool.
Private
The text and numbers you enter stay in your browser and are never uploaded.
Free
No signup and no paywall to use any tool in this set.
Works offline
Once the page has loaded it keeps working on a weak or dropped connection.
Built for developers
Plain inputs and outputs you can copy straight into code, configs, or notes.
Honest by design
Conversions and heuristics are for everyday and learning use; verify security-critical output with trusted, official tools.
Common uses
Aspect Ratio in responsive-layout planning
Use it when planning a wall mount or desk
Use it for quick screen-dimension reference
Use it for a gaming-setup decision
Use it for photography and print sizing
Use it when checking a screen fits a space
Technical notes
Aspect Ratio Calculator reduces the width:height ratio by their greatest common divisor, and solves for a missing side at a fixed aspect ratio.
Results are reference values; validate against your own environment before relying on them in production.
Nothing you type is uploaded — the calculation happens entirely on your device.
Worked example
A 1920 × 1080 image simplifies by dividing both by 120: 1920:1080 = 16:9.
FAQ
How is the ratio simplified?
The width and height are divided by their greatest common divisor, so 1920 by 1080 reduces to 16 by 9.
How is the new height found?
The new height is the new width multiplied by the original height and divided by the original width, preserving the proportions.
Is the new width required?
No. The ratio and decimal are shown from width and height alone; the new width is optional for scaling.
What is the decimal ratio?
It is the width divided by the height, so a 16 by 9 frame has a decimal ratio of about 1.7778.