Interest Savings Rate Calculator
Use this interest savings rate calculator to project a starting balance and regular deposits, then compare the stated nominal rate with its effective annual rate.
Written and checked by TheToolNet Editorial Team · Last reviewed: September 27, 2026 · Editorial method
Calculate savings interest
Nominal rate versus effective annual rate
A nominal rate describes the quoted annual rate before within-year compounding. Effective annual rate (EAR) includes that compounding: EAR = (1 + nominal rate ÷ periods)periods − 1. A 4.5% nominal rate compounded monthly is therefore slightly more than 4.5% effective.
How deposits are treated
Every deposit is added at the end of its selected compounding period. Choose monthly only when both interest and deposits are modeled monthly. For daily compounding with real monthly deposits, use a detailed account schedule instead of pretending that a deposit arrives every day.
Use a range, not one promise
Rates may be variable and promotional conditions may expire. Compare the advertised rate, effective rate, fees, minimum balances, withdrawal rules, tax, and deposit protection. This page does not fetch or recommend current bank products.
Compound-growth reference
Investor.gov's compound interest calculator likewise separates an initial investment, contributions, years, estimated rate, and frequency. You can also model exact daily periods with the daily compound interest calculator.
Frequently asked questions
Is APY the same as effective annual rate?
They commonly describe the one-year yield after compounding, but disclosures, fees, and jurisdiction-specific definitions can differ.
Are taxes included?
No. Interest taxation depends on the account and your jurisdiction.