How to calculate overnight buying power

So let’s say I have a strategy that only holds positions overnight. For example, everyday I buy using market-on-close orders and close those positions the next morning using market-on-open orders. No other trading during the day. Is my buying power just equity * 2 or is it more complicated than that? Thanks in advance

If it helps anyone else the answer seems to be equity * 2 but you also need to change your day trade buying power check to “block on exit” or else you will not be able to open the positions at market close after day 1.