i think it would be best to withdraw 1% of your balance every month. this way, as long as you are averaging more than 1% a month, you have nothing to worry about. if you have a £200k account, and average 5% a month, in the first month your acount increases to £210k, so you take out £2100 and leave the remaining 4% in the account. the month after that, you take out £2183, leave the remaining 4% in the account and etc etc. your account keeps compounding, your monthly income also compounds and you don’t have to worry about taking too much. one downer is you need a big account to be able to withdraw a decent amount of money to live on.