# Aspect Ratio Calculator

URL: https://speedycalculator.com/calculators/other/aspect-ratio/
Last updated: 2026-10-25

> The aspect ratio calculator resizes images, videos and screens while keeping proportions. Enter the original width and height and a new width to get the matching height, plus the simplified ratio.

## Inputs

- Original width
- Original height
- New width

## Results

- New height
- Ratio width
- Ratio height
- Decimal ratio

## Formula

```
New height = new width × original height ÷ original width
```

## Explanation

Keeping the aspect ratio avoids stretched or squashed images. Common ratios are 16:9 for video, 4:3 for older screens and 1:1 for social posts.

### How to use the Aspect Ratio Calculator

- **Original width**
- **Original height**
- **New width**
- Want to work backwards? Type a value into **New height** and **New width** is calculated for you.

Results update as you type, and every field accepts the units shown in its menu.

### How it works

The ratio is simplified with the greatest common divisor and the new height is scaled in proportion.

### Inputs explained

FieldWhat to enterOriginal widthA numberOriginal heightA numberNew widthA number

### What each result means

- **New height** = [New width]×[Original height]÷[Original width]
- **Ratio width** = [Original width]÷gcd([Original width], [Original height])
- **Ratio height** = [Original height]÷gcd([Original width], [Original height])
- **Decimal ratio** = [Original width]÷[Original height]

### Example values

How the main result changes when **New width** changes and everything else stays at the example values above:

New widthNew height6403609605401,2807201,6009001,9201,0802,5601,440

## Worked example

Inputs — Original width: 1,920; Original height: 1,080; New width: 1,280.

Results — **New height = 720**; Ratio width = 16; Ratio height = 9; Decimal ratio = 1.7778.

## FAQ

**What is 1920 × 1080 as a ratio?**
16:9.

**Why do some ratios look odd, like 64:27?**
That is 21:9 “ultrawide” expressed exactly.

**What formula does the Aspect Ratio Calculator use?**
New height = new width × original height ÷ original width.

**Can I work backwards from the result?**
Yes. Type the result you want into New height and the calculator finds the matching new width.