Aspect Ratio Calculator
Calculate, simplify, and solve missing dimensions for any aspect ratio.
1920 × 1080
16:9
Common Aspect Ratio Presets
Standard
Social Media
Cinema
Understanding Aspect Ratios
An aspect ratio is the proportional relationship between a rectangle's width and height, expressed as two integers separated by a colon (e.g. 16:9) or as a decimal (≈ 1.7778). When resizing images or videos without distortion, both dimensions must maintain that ratio. To find a missing dimension, divide the known dimension by the ratio's corresponding part and multiply by the other part — this tool does that arithmetic automatically. The simplification uses the greatest common divisor (GCD), so 1920×1080 correctly reduces to 16:9 rather than staying as 1920:1080. All math runs locally in your browser.
Related tools: Image Resizer · Image Compressor
Private & free — this tool runs entirely in your browser.