Aspect Ratio Calculator
Two modes. Mode 1 — resize while keeping ratio: enter the original width and height plus one new dimension, get the matching dimension that preserves the aspect ratio. Mode 2 — find ratio from dimensions: enter any width and height, get the simplified ratio (e.g. 1920×1080 → 16:9) plus the decimal value. Useful for video aspect ratios (16:9, 21:9), social-media images (1:1, 4:5, 9:16 for Reels/TikTok/Stories), monitor and TV sizing, and responsive design breakpoints. Runs locally in your browser.
Privacy
Runs entirely in your browser — nothing is sent to any server.
Cost
Free. No sign-up, no watermark.
Type
Calculator
Related tools
Tools that work with the same formats — most users open one of these next.
BMI Calculator
Compute Body Mass Index from height and weight in either metric or imperial units.
Percentage Calculator
Compute percent of a number, the percentage one number is of another, and percentage change.
Age Calculator
Compute your age in years, months, and days from a date of birth — plus total days lived.
Date Difference Calculator
Compute the difference between two dates in years, months, days, hours, minutes, seconds.
Tip Calculator
Calculate tip and split a restaurant bill across any number of people.
Timezone Converter
Convert a time from any timezone to any other — Central to Pacific, UTC to Tokyo, you name it.
Frequently asked
Is Aspect Ratio Calculator free to use?
Yes. Aspect Ratio Calculator is completely free with no sign-up, no watermark, and no usage limits. Toolsly does not charge for any of its tools.
Do my files and data stay private?
Yes — Aspect Ratio Calculator runs entirely in your browser using your device's CPU. Files and text are never uploaded to our servers, so your data stays private.
How does Aspect Ratio Calculator work?
Open Aspect Ratio Calculator, paste or fill in the input fields, and the result updates instantly. Everything runs in your browser — no upload, no waiting.
Which browsers does Aspect Ratio Calculator support?
Any modern browser works — Chrome, Firefox, Safari, and Edge on desktop and mobile. Aspect Ratio Calculator uses standard web APIs and does not require any plugin, extension, or sign-up.