THE NUMBERS, EXPLAINED
How to use this calculator.
Preserves aspect ratio using a target width; height rounds to the nearest pixel. No image file is resized by this calculator.
Start with your inputs
Enter original width (px), original height (px), target width (px). Keep amounts in the units shown on each field. The example is a starting point, not a recommended value.
| Input | Example value |
|---|---|
| Original width (px) | 1920 |
| Original height (px) | 1080 |
| Target width (px) | 960 |
A worked example
With the example inputs above, scaled height (px) is 540. Change the inputs to explore your own scenario.
Putting the example numbers into the formula
Scaled height (px)
round((960) × (1080) ÷ (1920)) = 540
Scale (%)
(960) ÷ (1920) × 100 = 50
| Result | Example answer |
|---|---|
| Scaled height (px) | 540 |
| Scale (%) | 50 |
How this is calculated
Scaled height (px)
round(c × b ÷ a)
Scale (%)
c ÷ a × 100
Symbols and units
- a
- Original width (px)
- b
- Original height (px)
- c
- Target width (px)
Use the units shown. A list keeps the order in which you enter its values. The symbol ^ means “raised to the power of”.
Calculation steps and notation
round(x) rounds to the nearest integer, with exact halfway ties towards positive infinity.
Assumptions and limits
Preserves aspect ratio using a target width; height rounds to the nearest pixel. No image file is resized by this calculator.
Calculations use the values you enter. Blank or invalid inputs show an error instead of silently substituting zero. Results are displayed to useful precision; calculations retain the underlying numeric precision.
Questions about this tool
What does the result tell me?
Scaled height (px); Scale (%). The result applies to the method and inputs described above. Check the units and assumptions before using it in a decision.
Why might another calculator differ?
Differences in units, rounding, timing or model definitions can produce different answers. Compare the input definitions and the method, rather than only the final number. For this tool: Preserves aspect ratio using a target width; height rounds to the nearest pixel. No image file is resized by this calculator.
Are my inputs stored or sent to AI?
Calculations on this page happen in your browser. The separate AI question finder sends its submitted conversation to OpenAI; these calculator fields are not sent. Favourites and recent tool names are stored locally. A shared link contains the inputs you choose to include.
Review status
Software example and browser checks are recorded in our quality report. No external expert review is claimed. Created with coding assistance; calculations run as ordinary browser code.
Read the quality report →