Keep the same ratio.

Simplify two numbers, set a new width or height and get the matching dimension automatically.

1 Enter ratio2 Scale one side3 Copy size

Width / first numberHeight / second number

Simplified ratio: 16:9

Which side are you setting?New width

Keep the same proportion

1,080 × 607.5

Height is calculated automatically so the original ratio stays intact.

What next?

Finish the next little job.

Percentage calculatorWork out increases, decreases and percentages without rearranging the formula.Open tool →Resize & crop imageUse the ratio on an actual image next.Open tool →Social resizerTurn the ratio into a platform-ready social size.Open tool →

Worth knowing

Ratios are useful because they survive resizing.

1920×1080, 1280×720 and 640×360 all share the same 16:9 proportion. Simplify first, then scale one side when you need a new size.

Before you use it

Use the same units on both sides.

A ratio only describes proportion. Pixels with pixels, centimetres with centimetres, and so on. Mixing units will give a mathematically valid but practically useless result.

The annoying bit

You changed the width. Now the height has become homework.

The design, crop or frame is already right. You only need the matching second dimension without stretching it out of shape.

Got another annoying job?

What’s the annoying thing you need done?

We’ll probably have a monkey for it. If we don’t yet, tell us what keeps wasting your time.