Calculating funding charges
Funding charges are calculated differently dependent on your provider, what leveraged product you are using and what market you are trading. For example, at IG funding charges for spread betting or CFD trades are the same, but are based on interbank rates (like LIBOR) for stocks and tom-next rates for forex.
Forward contracts or bets will not incur any funding charges, as the cost to keep them open is taken care of via the spread or commission charge. There is also no cost to keep a share dealing trade open, because share dealing trades are not made using leverage.