AMEX interest calculation??

[Anonymous]

So my 0% interest period is over mid December. I've carried a balance of about $900 just about every month (don't ask). (I've never missed a payment or anything like that). Now that my promotion is ending and there's still a balance, how is the interest calculated? My rate is 22%. What can I expect my balance to be after statement cuts??

[Anonymous]

Interest is not charged retroactively if that's your concern. For an interest charge calculation for your upcoming billing cycle, please dial the number on the back of your card.

[Anonymous]

Just take your APR of 22%, divide it by 12 and you get 0.0183% per month and multiply it by your $900 balance to get $16.50 then add it to your $900.

Each time you pay then take your statement balance and do it again. Close enough.