What size circuit is needed to run 3000 sq. foot house and 3 rv at same time

Circuit?

Do you mean service entrance size?

There is no single formula or chart, but a whole process that is easier done by someone with experience, rather than try to explain all the varibles.

In addition to the square footage of 3000 SF, need to know all major electric appliances amps or watts and voltage rating, type and electric ratings of heat and AC, hot tubs, etc.

Size amp or wattage needed for each RV.

I agree with tk!! Need more info.