Only with 2nd plane reticles. With a 1st plane reticle the mil / moa spacing remains the same through the entire zoom range, but the reticle gets "fatter" as you zoom higher, essentially just the opposite of what you would want to happen visually.

Half the power from the 1 mil spacing zoom setting, double the space in mils or MOA between the dots and the size of the dots. Double the power, half the spacing. You can also calculate fractional settings.

I prefer a zoom to be calibrated at 1 mil spacing in the lower power range so that the mil dots aren't so HUGE. I would prefer a 1/4 MOA or smaller dot size at the highest power setting. Even better is to get rid of the old fashioned dots and replace them with nice thin horizontal lines. They used dots in the past mainly because reticles were made of wire. Now days, almost all higher end scopes have laser etched glass reticles so they can use really nice lines like those found on the Nightforce NP-R1 or the Zeiss 1000 yard reticle.