Instantly calculate and convert aspect ratios

Instant, no sign-up.

Try a size
Result

How aspect ratio works

An aspect ratio is the proportional relationship between a width and a height, written as two numbers separated by a colon (like 16:9). To simplify a ratio, both numbers are divided by their greatest common divisor (GCD) - so 1920x1080 and 1280x720 both reduce to 16:9, because they describe the same shape at different sizes. To resize to a target ratio, the known dimension is multiplied by the ratio's other side and divided by the ratio's matching side.