Summary

This is a customizable measuring cup that doesn't require supports for printing. Although it fails on Thingiverse's Customizer, it runs fine on my PC running OpenSCAD version 2020.11.11. I've included STL files for three sizes (25, 50, and 100 ml) for your convenience, each designed for a maximum overhang angle of 60 degrees when printed upside-down. For customized versions, you'll need to specify the maximum desired overhang angle, the outer diameter, and the wall thickness. The volume in ml is automatically printed on the bottom; if you don't want this you can set the font scale factor to zero.

You'll have to use trial and error to get the exact volume you're after. The math would have prohibitively complicated to calculate the cup's dimensions from the volume.