Aspect Ratio Calculator

Calculate and convert aspect ratios for images and video. Find dimensions, resize proportionally, and browse social media presets.

Calculate Aspect Ratio

Enter width and height to find the simplified aspect ratio.

Aspect Ratio
Decimal
Megapixels

Find Missing Dimension

Enter an aspect ratio and one dimension to calculate the other.

Calculated Width
Calculated Height

Resize Calculator

Enter current dimensions and a target width or height to resize proportionally.

New Width
New Height
Megapixels

Common Aspect Ratios

Ratio Decimal Common Use

Social Media Presets

Click any preset to load its dimensions into the calculator above.

Platform Type Dimensions Ratio

Frequently Asked Questions

How do I calculate the aspect ratio of an image?
Enter the width and height of your image in pixels. The tool instantly calculates and simplifies the aspect ratio (e.g., 1920x1080 becomes 16:9) and shows the megapixel count.
How do I find the missing dimension for a specific aspect ratio?
Select or enter an aspect ratio (e.g., 16:9), enter either the width or height, and the tool calculates the other dimension to maintain the exact ratio.
What are the correct image sizes for social media?
This tool includes presets for Instagram posts (1080x1080), Instagram Stories (1080x1920), YouTube thumbnails (1280x720), Facebook covers (820x312), Twitter headers (1500x500), and LinkedIn banners (1584x396).
Is my data safe when using this aspect ratio calculator?
Yes. All calculations happen entirely in your browser. No data is ever sent to a server.