Calculate width or height from a target aspect ratio, use presets and preview the resulting shape.
Enter values, then calculate.
How the calculation works
Choose a ratio or enter positive ratio components. Edit width to derive height, or height to derive width. Height = width × ratio height ÷ ratio width; the inverse gives width. Pixel dimensions are rounded to the nearest whole pixel. The reduced output ratio is computed from those rounded dimensions using the greatest common divisor.
Example and verification
At 16:9, width 1,920 gives height 1,080 and reduced ratio 16:9. Width 101 gives height 57: rounding slightly changes the exact ratio. Tests cover both edit directions and every preset.
Software checks cover the example, invalid input, zero or boundary cases, and reset in Chromium. No physical measurements or all-browser certification are claimed.
Scope and limitations
This calculates dimensions; it does not upload, crop or resize an image. Supported pixel dimensions are whole numbers from 1 to 1,000,000; ratio components may be decimal. The preview is scaled to fit the screen and is not shown at actual pixel size.
Common questions
Why does the reduced ratio differ from the preset?
A whole-pixel dimension may require rounding. The reduced ratio describes the actual rounded pair.
Technical references
Related calculators
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Maintained by GadgetsFocus. Updated 2 October 2026 with AI-assisted writing and translation review; no human native-speaker or clinical review is claimed.