Aspect Ratio Calculator
Find missing image dimensions from a ratio, or calculate the aspect ratio from width and height. Common ratio presets included.
How to use the Aspect Ratio
Common aspect ratios
16:9 — widescreen video, YouTube, most modern monitors. 4:3 — old TV, iPad. 1:1 — Instagram square, profile pictures. 21:9 — ultrawide cinema. 9:16 — phone video (TikTok, Reels, Stories). 3:2 — DSLR photo standard. 4:5 — Instagram portrait.
Scaling correctly
Enter your original dimensions and target width (or height). The other dimension is automatically calculated to maintain the exact ratio. Use this when resizing photos, creating thumbnails, or preparing images for different platforms.
Frequently asked questions
Is the Aspect Ratio free to use?
Yes, the Aspect Ratio is completely free. There is no sign-up, no account required, and no limit on how often you can use it.
How accurate is the Aspect Ratio?
The Aspect Ratio uses standard mathematical formulas and produces results accurate to standard precision. For critical applications, always verify with an authoritative source.
What devices does the Aspect Ratio work on?
The Aspect Ratio works on any device with a modern web browser — desktop, laptop, tablet, or phone. It is mobile-friendly and works offline once the page has loaded.