Assumptions
The entered yield stays fixed for the whole projection.
Actual savings-account rates can change. Deposits, withdrawals, balance tiers, promotional periods and interest-crediting rules can also alter the result.
Savings calculator
Savings Interest Calculator
Project a savings balance from an initial deposit, recurring monthly contributions and a fixed annual percentage yield.
Projected ending balance—
Interest earned—
Total deposits—
Deposits and modeled yield
Initial deposit—
Recurring contributions—
Monthly rate equivalent to APY—
—
—
Method
The calculator converts the entered APY to an equivalent monthly rate using (1 + APY)^(1/12) − 1. It applies interest monthly and adds each contribution at the selected point in the month.
Interpretation
APY makes annual account yields comparable.
APY includes the effect of compounding over one year. This tool uses APY directly rather than applying a second compounding assumption.
Source
APY reflects interest and compounding.
The US Consumer Financial Protection Bureau defines APY as the amount of interest paid on an account based on the interest rate and frequency of compounding.
Consumer Financial Protection Bureau — Annual Percentage Yield calculation