Finance & Money
Savings Account Interest Calculator
Convert the entered nominal annual rate and compounding frequency to APY, then compound the opening balance and recurring end-of-month deposits.
Effective annual percentage yield-
Projected ending balance-
Opening balance plus deposits-
Modeled interest earned-
Average interest per month-
Interest share of ending balance-
Decision view
Savings deposits and interest growth
Savings deposits and interest growthMonth is shown against total balance, cumulative deposits, and cumulative interest.
Exact scenario comparisonNominal annual rate (%) changes while all other entered assumptions remain constant.
| Nominal annual rate (%) | Effective annual percentage yield | Projected ending balance | Opening balance plus deposits | Modeled interest earned | Average interest per month | Interest share of ending balance |
|---|
Period-by-period detail
Savings-account monthly and annual growth
How to use Savings Account Interest Calculator
- Enter the account's nominal rate and compounding frequency.
- Use a sustainable recurring deposit.
- Compare ending balance, deposits, and interest rather than the total alone.
Calculator guide
Understanding Savings Account Interest Calculator
Savings growth combines deposited cash with interest, so the balance path should keep principal contributions and bank-paid growth visibly separate.
Calculation method
How the calculation works
Convert a savings-account interest rate to APY and compound the opening balance plus recurring end-of-month deposits through the selected period. Derive APY from the nominal rate, project recurring deposits over the entered years, and subtract all deposited principal from ending balance to isolate modeled interest.
Balance anatomy
Separate saving behavior from bank yield
The same ending balance can result from very different combinations of deposits and interest.
Worked situations
Practical examples
- Monthly deposits made earlier have more time to earn interest.
- APY can differ from a nominal rate because of compounding.
- A variable-rate account will not follow one fixed projection.
Better inputs
Useful tips
- Update the rate when the bank changes it.
- Include fees as a separate budget item.
- Reconcile the projection with statements periodically.
Before relying on the result
Limitations and common mistakes
- Daily balance methods, variable rates, tiers, fees, bonuses, taxes, and deposit dates are simplified.
- Deposits are modeled at month end.
- The result is not an account quote.
Reference
Key terms
- Nominal rate
- Entered annual rate before compounding is converted to APY.
- APY
- Annualized yield including the entered compounding frequency.
- Deposited principal
- Opening cash plus recurring deposits.
- Interest share
- Modeled interest divided by ending balance.
Important note
Calculated from the entered values and stated financial terms. It is not a product quote, lending decision, tax filing, or investment recommendation.
Frequently asked questions
Why calculate APY?
It makes the effect of the entered compounding frequency explicit.
When are deposits assumed?
At the end of each modeled month.
Does the result include tax?
No.
Can I use a variable APY?
Use the entered rate as one scenario and update it when rates change.