Find the simplified aspect ratio of any width and height, such as 16:9 or 4:3.
Try an example
Load a ready-made sample into this tool and run it. Every result you see is calculated live by the tool itself — nothing here is a pre-written answer.
Sample: width: 1920; height: 1080
How to Use
- Enter a width and a height in pixels.
- Click Run.
- Read the simplified ratio and its decimal form.
Simplify any width and height to a ratio
This image aspect ratio calculator takes a width and height in pixels and reduces them to their simplest ratio, such as 16:9 or 4:3, along with the decimal form. Enter the two numbers and the tool does the reduction for you, which is quicker and more reliable than dividing by eye when dimensions run into thousands of pixels. It also shows the decimal form alongside the simplified ratio.
Useful wherever sizes must match a format
Ratios are how screens, video frames, print sizes and platform image slots are specified, so the calculator helps when you are checking whether an image will fit a slot without distortion, planning a crop, or comparing an export against a required format. Knowing the ratio first tells you whether resizing alone works or cropping is unavoidable.
Good to know
Ratios are reduced by their greatest common divisor, so 1920 by 1080 and 1280 by 720 both simplify to 16:9. The result describes proportions only, not a specific size: two images can share a ratio while one has many times the pixels of the other.
Frequently asked questions
What does the decimal form of a ratio mean?
It is the width divided by the height as one number: 16:9 gives about 1.78, meaning the image is 1.78 times as wide as tall. Some tools and CSS properties accept either form.
Why is my ratio an unusual pair of numbers?
Because the dimensions do not reduce to a famous ratio. A size like 1200 by 628 reduces to 300:157, exact even if not a standard label. Common ratios appear only when dimensions were chosen for them.
Does this tool resize my image?
No. It only calculates: you type a width and height and get the simplified ratio and decimal back. No file is involved, so use the Image Resizer or Image Cropper to change pixels.
How to use Image Aspect Ratio Calculator
- Enter a width and a height in pixels.
- Click Run.
- Read the simplified ratio and its decimal form.
Limitations
Ratios are reduced by their greatest common divisor; the result describes proportions, not a specific size. Files are processed in your browser and never sent to the site's server.