This script will generate a measuring cup while also doing all the calculations for you! Written in OpenSCAD, so it can even be rendered on the classic Raspberry Pi.

Give your desired outer diameter (in millimeters) and required internal volume (in milliliters), and it will calculate the height, keeping the wall thickness into account too. The handle is parametric as well in both length and width.

A second smaller volume is marked with a line inside, for example smaller amounts of laundry.

The volumes are also embedded in the bottom of the cup, in two separate heights to allow triple colour printing with a single extruder.