Your Compound Growth Summary
Your modeled ending balance is —, including — of interest.
- Initial Amount
- —
- Regular Contributions
- —
- Annual Interest Rate
- —
- Compounding
- —
- Investment Length
- —
- Contribution Timing
- —
After the modeled period, your projected balance is —.
You put in — including the starting amount and modeled contributions.
The projection attributes — to modeled interest growth.
At the assumed inflation rate, the projected balance has estimated purchasing power of — in today's terms.
Interest is added to the balance and can itself earn future interest. Regular contributions and their timing also affect the final balance.
Finance calculations are estimates based on the values and assumptions you enter. They are not financial, tax, lending or investment advice. Verify the terms, rates, fees and local rules that apply to your situation.
About this tool
Compound Interest Calculator
Use this free compound interest calculator to estimate future value from an initial amount and regular contributions. Choose monthly, quarterly, semi-annual or annual compounding, compare total contributions with interest earned, and optionally estimate inflation-adjusted purchasing power and a simplified after-tax scenario.
What This Compound Interest Calculator Does
Use this free compound interest calculator to estimate how an initial amount and regular contributions could grow over time when interest is compounded. The result shows your projected ending balance, total contributions, total interest and an inflation-adjusted value.
Inputs and What They Mean
Enter your starting amount, annual and/or monthly contribution, annual interest rate, compounding frequency, investment length and contribution timing. Optional tax-on-interest and inflation assumptions let you compare different planning scenarios.
How Compound Interest Is Calculated
For each compounding period, the calculator applies the periodic rate to the current balance. Contributions are added at the beginning or end of the period according to your selection. Because earned interest remains in the balance, later periods can earn interest on earlier interest.
How to Use the Compound Interest Calculator
- Enter your starting amount and planned contributions.
- Enter the annual interest or return assumption.
- Select monthly, quarterly, semi-annual or annual compounding.
- Choose whether contributions are made at the beginning or end of each period.
- Enter the investment length and optional tax and inflation assumptions.
- Select Calculate and review the result dashboard.
- Change one assumption at a time to compare scenarios.
How to Interpret the Result
The ending balance is the projected value under your assumptions. Total contributions show the starting amount plus modeled deposits, while total interest is the growth attributed to the compounding calculation. The inflation-adjusted value estimates purchasing power after applying the selected inflation assumption.
Important Assumptions and Limitations
This calculator provides a mathematical projection, not a guaranteed investment return. Real investments can have variable returns, fees, taxes, withdrawals and losses. The optional tax estimate is a simplified scenario and is not a jurisdiction-specific tax calculation.
Practical Planning Tip
Compare conservative, base and optimistic scenarios instead of relying on one assumed rate. Verify current rates, fees, taxes, account rules and local regulations with the relevant provider or official source before making financial decisions.
Questions & Answers
Frequently Asked Questions
Does compound interest guarantee an investment return?
No. The calculator projects a constant assumed rate. Actual investment returns can vary and may be reduced by fees and taxes.
Does compounding frequency affect the result?
Yes. Monthly, quarterly, semi-annual and annual compounding produce different results when the quoted annual rate is held constant.