Betfair uses decimal odds which are inclusive of stake. So, a winning bet of £10 at odds of 6 would result in a return of £50 profit + your £10 stake =£60.

All odds at Betfair are displayed from the backer's point of view. If you see 6 and £10 on the 'Back' side of the screen, you may also see 7 and a stake of £10 on the 'Lay' side of the screen. The 7 is a bet posted by a backer who wants to back that selection at 7; he/she wants better odds than 6. If you match this 7 bet for the full £10 requested by clicking 'Lay', you'll be betting against that selection and you'll be risking £60 to win £10.