Formulas for bookmaking

[gwftrading]

Hi,

I am building a spreadsheet to lay multiple horses in an event. Does anyone know the formulas used in the BA bookmaking section, to calculate each stake. I am seeking all three formula depanding on which of the three staking methods are used.

Thanks
GF

[Bet Angel]

Same as on the Betfair site, it's your stake * (1/odds)

[gwftrading]

Thank you