This is the math needed to calculate the interest rate you get on a savings account per month when you know the interest rate per year.
A savings account earns an annual rate of 3.95%. What is the monthly interest rate?
Convert the Percentage to a Decimal
To convert a number into a decimal, take the number without the percent sign and divide by 100.
Change to a Monthly Rate
Take the answer (.0395) and divide by 12 (the number of months).
Convert Back to a Percent
Take the monthly rate and multiple by 100.
Your interest rate per month is .33%.
Interest Rates, Compounding, and APY