Ever had one of these questions?

How many pixels wide is an image with 25.17 cm? At what DPI? Lets say... 300. And at 72 DPI?
How many pixels high is an image with 7.3 inches at 96 dpi?
If my image is 2400 pixels wide, how many centimeters will I be able to print it, at 150 DPI?
I just rendered a 1230 by 708 pixels image. Now I need it with 3290 pixels wide. How many pixels high will it have, proportionally?

You probably had to fight with these doubts already, specially because Cinema4D only works with pixels. And, when a new dimension is entered, there is no proportional adjustment of the other dimension.

This is exactly what CalcSize does. It does all conversions for you, keeping them proportional, optionally.
It will also provide additional information on the size of the resulting image in greyscale and RGB.
And, if that was not enough, you can even automatically set the Render Settings automatically from CalcSize. It couldn't be easier!