# Working out Percentage

#### lave48

##### New member
I have an account that pays 2.1% per annum. The amount in the account has varied over the year due to withdrawals. My question is what is the formula for working out the interest due to me over the year? Many thanks in advance Lave48

#### Country Boy

##### Well-known member
MHB Math Helper
Precisely what happens depends upon the policy of the bank. Most likely, and certainly the most exact, would be to deal with individual days. An interest rate of 2.1% per year is 2.1/365= 0.00575% per day. Calculate the interest for each day with the amount of money that day.

#### Wilmer

##### In Memoriam
I have an account that pays 2.1% per annum. The amount in the account has varied over the year due to withdrawals. My question is what is the formula for working out the interest due to me over the year? Many thanks in advance Lave48
...or calculate the average balance for the year;
multiply result by .021

Example: if av.bal. = 1200, then 1200*.021 = 25.20
Enough for a 12pack of beer!!