Aspect Ratios Explained: Calculate Perfect Dimensions for Any Use

What Is Aspect Ratio?

Aspect ratio is the proportional relationship between width and height. It's expressed as W:H — for example, 16:9 means for every 16 units of width, there are 9 units of height.

Common Aspect Ratios

• 16:9 — HD video, YouTube, most monitors
• 9:16 — TikTok, Instagram Reels, YouTube Shorts
• 4:3 — Classic TV, presentations, iPad
• 1:1 — Instagram posts, profile pictures
• 4:5 — Instagram portrait posts
• 21:9 — Ultrawide monitors, cinema

Calculate Dimensions

Use our Aspect Ratio Calculator to find the missing dimension given a ratio and one side. Includes presets for social media and video platforms.