How the calculation works
For a ratio a:b, a known width W gives a height of W × b ÷ a. A known height H gives a width of H × a ÷ b. The calculator preserves full precision, then labels the nearest whole-pixel result separately.
Worked example
With a 16:9 ratio and a width of 1000 pixels, the mathematical height is 562.5 pixels. The nearest whole-pixel height is 563 pixels, which is an approximation.
Limits
Ratio terms must be whole numbers from 1 to 10000. Pixel dimensions and calculated results must stay from 1 to 100000. Aspect ratio describes shape, not image quality.