Thumbnail Size Fitter
Fit an image down to a maximum width and height without distortion.
About Thumbnail Size Fitter
The smaller of the two width or height ratios is chosen as the scale, capped at one to avoid enlarging, then original pixels are multiplied by it. Aspect-safe downscaling keeps thumbnails sharp and undistorted, meeting platform limits like YouTube's 1280x720 cover without breaking a crop.
Formula
Thumbnail Size Fitter
Scale = min(maxWidth / width, maxHeight / height, 1)
- fit
- Largest scale that fits both max dimensions
Worked example
With the default values below, Thumbnail Size Fitter returns Output Width of 960. Change any input above and every figure here is recalculated in your browser.
Inputs used
- Source widthminimum 1 px
- 4,000 px
- Source heightminimum 1 px
- 3,000 px
- Max widthminimum 50 px
- 1,280 px
- Max heightminimum 50 px
- 720 px
Results
- Output Width
- 960 px
- Output Height
- 720 px
- Scaled to
- 24%
Step by step
- 1Values used
- 2Thumbnail Size Fitter
- 3Output Width= 960 px
- 4Output Height= 720 px
- 5Scaled to= 24
Assumptions and limits
- The result is derived only from the 4 inputs listed above. Anything not among them is not part of the calculation.
- In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
- Figures are rounded for display to whole numbers, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.
How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.
Frequently Asked Questions
How is Thumbnail Size Fitter calculated?
Scale = min(maxWidth / width, maxHeight / height, 1) The smaller of the two width or height ratios is chosen as the scale, capped at one to avoid enlarging, then original pixels are multiplied by it.
Why does Thumbnail Size Fitter matter?
Aspect-safe downscaling keeps thumbnails sharp and undistorted, meeting platform limits like YouTube's 1280x720 cover without breaking a crop.
What values do I need to enter?
This calculator takes 4 inputs: Source width, Source height, Max width, Max height. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.