Media & Design
Aspect Ratio Calculator
Simplify a width and height to an aspect ratio, or find the missing side.
Results appear here.
What the result means
If width and height are both filled in, the page reduces them by their greatest common divisor and shows the ratio. Decimal sides are scaled to whole numbers first, up to six decimal places, and then reduced. If only one side is filled in, add a ratio such as 16:9 and the missing side is calculated from that pair. Zero and negative sizes are rejected, and so are zero or negative parts of a ratio. When the missing side is not already a whole number, it is rounded to one decimal place and the result says that it was rounded. A 16:9 frame is sixteen units wide for every nine units of height. Filling both sides takes priority, and the ratio box is not used in that case.
Related tools
Questions
What is 16:9?
It means the width is 16 units for every 9 units of height. A 1920 by 1080 picture is 16:9. Type 16:9 with one side filled in and the page computes the other side.
How is the ratio simplified?
The sides are turned into whole numbers and divided by their greatest common divisor. That is the largest whole number that divides both. 1920 by 1080 becomes 16:9 because 120 divides both.
Why was the missing side rounded?
It was not a whole number. The page rounds that side to one decimal and says so. The ratio you typed is not rewritten by that rounding.