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Aspect ratio calculator

The aspect ratio of a picture or screen from its pixels, and a new width or height that keeps its shape. Free, with no account or uploads.

Work out an aspect ratio

Type the width and height in pixels. Give a new width or height to keep the same shape.

Resize to a new
WidthHeight

1,920 × 1,080

16 : 9

The shape of HD and 4K video, most screens

At 1,280 pixels wide, the same shape is 1,280 × 720.

Yours
16:9
4:3
1:1
4:5
9:16

To change a picture to this size, use the Image resizer; to crop a video to another shape, use Crop video.

How it works and help
Every fraction is kept exact, step by step, on your device. Nothing you type is sent anywhere.

A little help along the way

Follow these steps. Everything is worked out exactly in your browser; nothing is sent anywhere.

  1. Say what you want to doWork with fractions is the usual. The others simplify a ratio, find x or share out a total, turn decimals and fractions into each other, and work with picture sizes.
  2. Type the numbersFractions as 3/4, mixed numbers as 1 1/2, ratios with colons as 12 : 18, and repeating decimals with brackets as 0.1(6).
  3. Read the answer and every stepThe answer is drawn as a textbook would, with each step under it.

Questions people ask

What aspect ratio is 1920 × 1080?
16:9, the shape of HD and 4K video and most screens. The page divides both sides by their largest common factor, 120.
What if my size is not an exact ratio?
The page gives the exact ratio, such as 683:384 for 1366 × 768, and the common shape it is within 1% of, here 16:9, with how far off it is.
How do I resize and keep the shape?
Type a new width or height and the other side is worked out, rounded to whole pixels. The page says when a video would want an even number.

This page is the Fraction and ratio calculator, opened for this one job; every other tool it has is one press away. Each of its settings is explained on the Fraction and ratio calculator's own page.

Read the step-by-step guide

Guides

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