Parametric Measuring Cup

This 3mf file is designed for a 1/8 C (18.6 ml). The volume is adjustable by changing parameters in the FreeCAD file's Params spreadsheet. Specifically there is a height (height of the straight-sided part of the cup) and the radius of curvature. The volume is easy to calculate with these parameters, as is done in the Python code. The Python code allows for calculating a radius needed to achieve a desired volume, though the height is hard-coded to be a factor of the radius.

I printed this for laundry detergent, but of course the same design would work for coffee, flour, or whatever else you want to measure.