Here's the reply from Marchscopes Deon:
"Thank you for your inquiry.
The dot size is at the magnification of 40X.
That means 1/8 dot covers 0.25 inch length at 100 yard and 1.25 inch at 1000 yard.
And 3/32 dot covers 0.094 inch at 100 yard and 0.94 inch at 1000 yard."
1/8" covers .125 at 100...... a 1/4" covers .250 at 100...... Jim