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Free aspect ratio calculator

Find any aspect ratio and resize without stretching

Enter a width and height, or pick a photo, to get its aspect ratio and the nearest standard one. Type a new width or height and the other side fills in.

Free, no sign-upRuns in your browserYour photos never leave your device

Calculate a ratio See pricing

1920 × 1080 simplified to 16:9, and a new width of 1080 px giving a height of 608 px

Free · runs in your browser

Aspect Ratio Calculator

No sign-up. Your photo never leaves your device.

Original size

Width

Height

Or read the size of a photo

Common ratios (keeps the width, sets the height)

New size, same ratio

New width

New height

Type a new width or a new height and the other one fills in.

Aspect ratio

–

As a decimal (width ÷ height)–

Orientation–

New size–

Megapixels (original)–

How it’s calculated

The ratio is the width and height divided by their greatest common divisor: 1920 × 1080 → ÷ 120 → 16:9.
Sizes with decimals are scaled to whole numbers first, so 1.5 × 1 becomes 3:2.
New height = new width × height ÷ width, and new width = new height × width ÷ height, rounded to whole pixels.
The nearest common ratio is shown when it is within 1% of yours.

Photo the wrong shape for a listing? Extend it to any ratio with AI →

Need more pixels for a bigger size? Upscale it with AI →

Features

Everything you need, nothing you don't

Simplest ratio

1920 × 1080 becomes 16:9, 1080 × 1350 becomes 4:5.

Nearest standard ratio

Odd sizes are matched to the common ratio within 1%, such as 1366 × 768 ≈ 16:9.

Resize in proportion

Type a new width or height and get the other side, rounded to whole pixels.

Common ratios

One click for 1:1, 4:5, 3:4, 2:3, 9:16, 4:3, 3:2, 16:9 and 21:9.

Read a photo

Pick a photo and its size fills in. It's read on your device, not uploaded.

Free

No account, no limits.

How it works

Done in 3 steps

Enter the size

Type a width and height, or pick a photo to read its size.

Read the ratio

See the simplified ratio, its decimal and the nearest common ratio.

Resize

Type a new width or height to get the other side.

FAQ

Questions about aspect ratio calculator

Is the aspect ratio calculator free?

Yes. It's free with no sign-up and no limits.

Is my photo uploaded?

No. If you pick a photo, your browser reads its width and height. The photo never leaves your device.

How is the aspect ratio calculated?

The width and height are divided by their greatest common divisor. 1920 and 1080 share 120, so 1920 × 1080 is 16:9.

What is the aspect ratio of 1080 × 1350?

4:5, the portrait shape many social feeds use. 1080 × 1080 is 1:1 and 1080 × 1920 is 9:16.

How do I resize without stretching?

Keep the ratio the same: new height = new width × original height ÷ original width. Type the new width and the calculator does this for you, rounded to whole pixels.

My photo is the wrong ratio. What can I do?

Crop it to the new ratio with the free image cropper, or add space around it. The AI image extender can fill new space with matching background instead of plain bars.

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