Interest Rate Calculator
When you know starting balance, ending balance, term, and contribution pattern, this tool backs into the implied annual interest rate. It is useful for...
Enter values and click Calculate.
Schedule
Introduction
When you know starting balance, ending balance, term, and contribution pattern, this tool backs into the implied annual interest rate. It is useful for reverse-engineering APY from account statements or evaluating whether an advertised return is realistic.
Solve for the Missing Rate
When you know starting balance, ending balance, term, and contribution pattern, this tool backs into the implied annual interest rate. It is useful for reverse-engineering APY from account statements or evaluating whether an advertised return is realistic.
Money-Weighted Return
Irregular deposits and withdrawals change the effective rate you experienced. The solver finds the constant annual rate that reconciles your cash flows to the ending balance—similar in spirit to IRR for a single account.
Common Use Cases
- Verify bank APY against actual statement growth.
- Compare two savings products with different contribution habits.
- Audit advisor or fund performance claims over a defined window.
Limitations
One constant rate is an approximation when market returns vary. For volatile portfolios, use the Average Return Calculator or IRR Calculator with dated cash flows.
Related Tools
Forward projections: Future Value Calculator. Present value discounts: Present Value Calculator.
How It Works
- Enter your amounts, rates, and term in the form. Use the same units shown in the labels (dollars, years, percent).
- Click Calculate to run the Interest Rate Calculator engine. Invalid or empty required fields show a clear error message.
- Review the summary cards for the key outputs. Expand schedules or tables when available for period-by-period detail.
- Copy, print, or share your scenario link. Reset the form anytime to start a fresh comparison.