Aspect Ratio Calculator

An aspect ratio describes the proportional relationship between width and height. When you scale an image or video, maintaining the aspect ratio prevents stretching or distortion.

The Formula

Given an aspect ratio of W:H and one known dimension, the other is calculated as:

• Height = Width × (H / W)
• Width = Height × (W / H)

Common Aspect Ratios

• 16:9 — Standard widescreen for HD/4K video and monitors
• 4:3 — Classic TV and older computer monitors
• 1:1 — Square format, common on social media
• 9:16 — Vertical video for mobile stories and reels
• 21:9 — Ultra-wide cinema and gaming monitors
• 3:2 — Common in photography (DSLR sensors)

Tips

• Lock the ratio to freely change width or height while keeping proportions
• Unlock the ratio to enter both dimensions independently — the calculator will detect the resulting ratio
• Use presets for quick access to standard ratios used in video, photography, and social media
• Results are rounded to the nearest pixel for practical use

You can embed this util on your own site as a widget. Adding ?embed=1 to the URL loads a compact version with just the tool itself; no header, menu, or documentation. Paste this snippet into your HTML:

Copy snippet Adjust the height to taste.