Image Aspect Ratio Calculator
Calculate image aspect ratios, find a missing width or height, and check against common preset ratios like 16:9 or 1:1.
Runs entirely in your browser — your files are never uploaded to a server.
How It Works
1. Choose Your File
Drag & drop or select the file you want to work with.
2. Processed in Your Browser
Everything happens locally on your device — your file is never uploaded anywhere.
3. Download Your Result
Get your finished file instantly, ready to save or share.
Frequently Asked Questions
How do I find a missing dimension?
Enter your target width (or height) and a ratio, leave the other field blank, and the tool calculates it for you.
What preset ratios are included?
16:9, 4:3, 1:1, 9:16, 21:9, 3:2, and 4:5 — covering widescreen video, standard photos, square, portrait/story, ultrawide, classic photo, and Instagram portrait formats.
Can I check if my existing dimensions match a specific ratio?
Yes, enter both width and height along with a target ratio, and the tool tells you if they match or what to change.
What does the simplified ratio mean?
It's your width and height reduced to their smallest whole-number equivalent, e.g. 1920×1080 simplifies to 16:9.