Aspect Ratio Calculator
Calculate and convert aspect ratios for images, videos, and screens. Find dimensions, resize proportionally, and maintain quality.
An aspect ratio calculator reduces a width and a height to their simplest whole-number ratio and works out the matching dimensions when you resize. The default 1920 by 1080 gives 16:9, 1.78:1, 2.07 megapixels, 2,073,600 total pixels, Landscape and the display standard Full HD; type a New width in the resize box and the New height follows in proportion.
Reduce whole-pixel dimensions to their exact width:height ratio, then resize from either axis without replacing the original dimensions.
Enter positive whole pixels, 1 to 1,000,000,000. No decimals, grouping or exponents.
Resize
Rounded to the nearest whole pixel; a half pixel rounds up. The resized ratio may differ slightly.
Presets are dimension examples, not current platform upload requirements. The preview keeps the ratio; very thin shapes may be difficult to see. This calculates dimensions and does not resize an image file.
Result
- Total Pixels
- Megapixels
- Orientation
- Display Standard
Method and limits
The greatest common divisor reduces the ratio. Pixel count is width × height; one megapixel is 1,000,000 pixels. The decimal ratio uses four places, megapixels two; ≈ marks rounding.
Rounded to the nearest whole pixel; a half pixel rounds up. The resized ratio may differ slightly.
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About Aspect Ratio Calculator
Reduce whole-pixel dimensions to their exact width:height ratio, then resize from either axis without replacing the original dimensions.
1920 × 1080 gives 16:9, 2,073,600 pixels and about 2.07 MP. Width 1280 gives height 720. A 3440 × 1440 preset reduces to 43:18, not exactly 21:9.
Arithmetic conventions only; no dated prices or platform rules.
Use Cases
How to use
Choose the mode or example, enter complete values, then read the labelled result.
The calculator keeps entered values while switching panels. Reset clears the editable draft.
Pro Tips
- Presets are dimension examples, not current platform upload requirements. The preview keeps the ratio; very thin shapes may be difficult to see. This calculates dimensions and does not resize an image file.
Frequently Asked Questions
A whole-pixel output rounds the calculated missing side. Keep the exact fractional side shown if your workflow permits subpixel dimensions.
Presets are dimension examples, not current platform upload requirements. The preview keeps the ratio; very thin shapes may be difficult to see. This calculates dimensions and does not resize an image file.