Aspect Ratio Calculator
Calculate aspect ratios and dimensions for images, videos, and displays with comprehensive analysis including diagonal measurements and area calculations. Perfect for video production, image editing, web design, and social media content creation.
Complete Guide: Aspect Ratio Calculator
Everything you need to know about using this tool effectively
Enter a width and height to calculate the aspect ratio, or enter an aspect ratio plus one dimension to find the missing width or height. The calculator simplifies ratios to their lowest terms and shows the diagonal measurement and total pixel area. Works for video, images, monitors, and any rectangular format.
The aspect ratio is the simplified ratio of width to height, found by dividing both dimensions by their greatest common divisor (GCD). For example, 1920x1080 reduces to 16:9 because GCD(1920, 1080) = 120. The diagonal is calculated using the Pythagorean theorem: d = sqrt(w^2 + h^2).
Video production
Determine the correct resolution for YouTube, TikTok, or broadcast standards based on the target aspect ratio.
Image resizing
Calculate new dimensions when scaling an image while preserving the original proportions.
Monitor and TV shopping
Compare screen ratios to understand the actual viewing area difference between ultrawide and standard displays.
Print design
Match photo or layout dimensions to standard print sizes like 4x6, 5x7, or 8x10 without distortion.
Enter width and height
Type your dimensions in pixels, inches, or any unit to get the simplified aspect ratio.
Or enter a ratio plus one dimension
Select a preset ratio like 16:9 and enter either the width or height to calculate the missing value.
Review the results
The calculator shows the simplified ratio, diagonal, area, and calculated dimensions.
Use the preset dropdown for common ratios like 16:9, 4:3, and 21:9 to save time
The diagonal measurement helps compare screens of different ratios with similar stated sizes
For social media, check platform-specific ratio requirements before resizing your content
Always scale both dimensions proportionally to avoid stretching or squishing your media
What is an aspect ratio?
An aspect ratio is the proportional relationship between the width and height of a rectangle. It is expressed as two numbers separated by a colon, such as 16:9, meaning the width is 16 units for every 9 units of height.
How do I find a missing dimension?
Enter the known aspect ratio and either the width or height. The calculator multiplies the known dimension by the ratio to find the other side. For example, a 16:9 ratio with a 1920-pixel width gives a 1080-pixel height.
What aspect ratio is my screen?
Most modern monitors and TVs use 16:9. Ultrawide monitors are typically 21:9. Older CRT monitors and some tablets use 4:3. You can measure your screen and enter the dimensions to confirm.
Can I use this for non-pixel measurements?
Yes, the calculator works with any unit of measurement including inches, centimeters, meters, and feet. The ratio is the same regardless of the unit used.
Why does the calculator simplify the ratio?
Simplifying to the lowest terms makes it easier to compare ratios and match them to standard formats. A 1920x1080 resolution and a 3840x2160 resolution both simplify to 16:9.
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