Create a new primitive, Cube or Cylinder in your Inches or Centimeters (whichever you like best)
Set it’s height dimension to 1 (for a cube, there’s only one dimension, so it’s simpler)
Go to the Y Scale Parameter, and change it’s option from Percent to Value
Then just dial that scale UP till it matches the height of your figure.
The value is equal to the height in either inches or centimeters (whichever you selected)
If you are SCALING a Figure, which I do often, set the value of your primitive (this is why I use cylinders, because I can set the diameter and have it stay constant).
For instance: A Woman of 5’6” will be 66 inches tall, so set the Cylinder to 66 inches when you’re creating it…