Scale Meter

Size "on eyes" or scale:
Try this: 54mm, 28mm, 1/9
Your creature real height:

Lines are interactive, move them with mouse. To add or remove lines - double click on field or use buttons.

Default Human Height:
Eyes are in % from top of the head: %
Precision, show 0-4 numbers after dot:
Take Screenshot
You can take screenshot of Scale Meter screen to use them somewhere.