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Aspect Ratio Calculator
Calculate dimensions, detect aspect ratios, and find matching common sizes for any ratio.
:
16:9
Ratio16:9
Decimal1.7778:1
Width1920px
Height1080px
Total pixels2.07 MP
About This Tool
Aspect Ratio Calculator finds matching dimensions when you change one side of an image or video frame. Enter a width and height to find the ratio, or enter a ratio and one dimension to calculate the other.
Common ratios include 16:9 (HD video, YouTube, most monitors), 4:3 (older displays, presentations), 1:1 (square, Instagram), 9:16 (TikTok, Stories), and 21:9 (ultrawide). The tool identifies standard ratios automatically.
Also useful for responsive web design: calculating breakpoint widths, maintaining video embed proportions, or finding dimensions for image placeholders. All calculations happen in your browser.