HesapHanem

Resolution Scaler

Resize a resolution without distortion.

How it is calculated

To keep the proportions the tool uses new_height = orig_height × new_width / orig_width. Width and height are in pixels. The ratio shown is the original width and height divided by their greatest common divisor, found with Euclid's algorithm after rounding both to whole numbers.

The new height is given to two decimals and is not rounded to a whole pixel, so a result such as 449.78 px must be rounded by you (to 450) before you use it, and the picture will then be a tiny fraction off the exact ratio. You can only set a new width; to scale from a height, swap the two original values and enter the target height as the width. The original width and height must be greater than zero. Sizes that share no common factor stay unreduced, for example 1000×667 shows as 1000:667.

Worked example

Scale a 1920 × 1080 image to a width of 1280. New height: 1080 × 1280 / 1920 = 1,382,400 / 1920 = 720.00 px. For the ratio, the greatest common divisor of 1920 and 1080 is 120, so 1920 / 120 = 16 and 1080 / 120 = 9, giving 16:9. The result is a 1280 × 720 image with the same shape as the original.

Try this example →

Common mistakes

  • Typing the new height in the new-width box. The tool always takes the new width and works out the height.
  • Using the result without rounding. A height like 449.78 px is not a real pixel size; round to a whole number, accepting a tiny change in ratio.
  • Expecting a clean ratio from a size such as 1366×768. It reduces to 683:384, not 16:9, because the screen is only close to 16:9.
  • Entering the width and height in inches or centimetres and expecting pixels. The proportion works in any unit, but the label says px.
  • Swapping original width and height, which makes a landscape image come out as portrait.

About this calculator

This calculator scales a resolution to a new width (or height) while preserving the original aspect ratio, computing new height = new width × (original height / original width), and also reduces the ratio to its simplest whole-number form (like 1920×1080 simplifying to 16:9) using the greatest common divisor of the two dimensions. Keeping the aspect ratio locked prevents the stretching or squashing distortion that happens when width and height are resized independently.

Video editors, graphic designers, web developers setting responsive image dimensions, and anyone resizing photos or video for a specific platform use this to get exact pixel dimensions that match the source proportions.

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Comments (1)

  • Editorial team

    Video encoders often want even pixel dimensions, and this tool does not round for you. Scaling 1920×1080 to a width of 854 gives a height of 480.38 px, so you would round to 480 and accept a ratio that is very slightly off 16:9. Decide on your rounding rule before you export. Tell us if you would like a nearest-even option, and for which kind of work.

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