Aspect Ratio Calculator
Find the simplified aspect ratio of any dimensions, scale images proportionally, and explore common ratio presets for video, photos, and social media.
Common Presets
Original Dimensions (px)
Simplified Aspect Ratio
16:9
Landscape (wide)
Scale proportionally
How to use the Aspect Ratio Calculator
- Enter the original width and height, or click a preset ratio button.
- The simplified ratio appears instantly (e.g. 1920×1080 → 16:9).
- To scale proportionally, enter a new width and click → Height, or enter a new height and click → Width.
Common aspect ratios
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All calculations run locally. No images or data are uploaded. No signup required.
Frequently Asked Questions
What is an aspect ratio?
An aspect ratio is the proportional relationship between an image's width and its height, expressed as W:H. A 1920×1080 image has a 16:9 ratio — the same as a 1280×720 or 640×360 image. It describes the shape without specifying the size.
Why does 1920×1080 simplify to 16:9 not 1920:1080?
The calculator divides both dimensions by their greatest common divisor (GCD). For 1920 and 1080, GCD is 120, giving 1920÷120 = 16 and 1080÷120 = 9.
How do I resize an image without distortion?
Use the proportional scaling tool above: enter the original dimensions, then enter your desired width (or height) and click the button. The calculator computes the other dimension that preserves the ratio exactly.