Finance calculator
Compound Interest Calculator
Calculate future value and compound interest from principal, annual rate, term, and daily, monthly, quarterly, or yearly compounding.
Principal growth with periodic compounding
Separate the nominal rate from how often interest is credited
Compound interest adds each period's interest to the balance, allowing later interest to be earned on both principal and earlier interest. The formula A = P(1 + r/n)^(nt) uses principal P, nominal annual rate r, compounding periods per year n, and time in years t.
Compounding frequency changes the periodic rate and number of periods. At the same nominal annual rate, monthly compounding generally produces a slightly higher future value than annual compounding because interest is credited sooner. This does not mean the advertised rate itself increased.
This calculator grows one starting balance without recurring deposits. Use a SIP, future value, or savings-goal calculator when contributions continue over time. Keep fees, tax, inflation, rate changes, and investment volatility outside this fixed-rate illustration.
| Reference | Value or meaning |
|---|---|
| Future value | A = P(1 + r/n)^(nt) |
| Interest earned | A - P |
| Monthly compounding | n = 12 |
| Quarterly compounding | n = 4 |
Checks before using the result
- Enter the annual rate as a percentage, not as an already divided periodic rate.
- Match daily, monthly, quarterly, or annual compounding to the product terms.
- Keep the term in years consistent with the annual rate.
- Compare the result with product APY, fees, taxes, and withdrawal rules before making a decision.
Sources and related tools
FormulaA = P x (1 + r / n)^(n x t)
Formula
Compound interest formula
Compounding projections are estimates. Actual returns can vary because of fees, taxes, market movement, and timing.
A = P x (1 + r / n)^(n x t)
10,000 at 8% compounded monthly for 5 years becomes 10,000 x (1 + 0.08 / 12)^60.
SourcesThis calculator includes source notes, assumptions, and exclusions so the result is easier to verify before use.
Sources and assumptions
Source notes
This calculator includes source notes, assumptions, and exclusions so the result is easier to verify before use.
- Effective year
- Current rules
- Last verified
- 2026-06-18
Compounding projections are estimates. Actual returns can vary because of fees, taxes, market movement, and timing.
Official and reference sources
Assumptions
- The annual rate remains constant for the full term.
- Interest is credited at equal intervals using the selected compounding frequency.
- No additional deposits or withdrawals occur during the calculation.
Not included
- Recurring contributions or withdrawals.
- Variable rates, fees, taxes, inflation, and investment volatility.
- Product-specific day-count rules and early-withdrawal penalties.
FAQ8 common questions for this calculator.
FAQs
What does compounding mean?+
Compounding means interest earns additional interest because it is added back to the balance.
Does compounding frequency matter?+
Yes. More frequent compounding usually increases the final amount slightly when the same nominal annual rate is used.
What inputs are needed for compound interest?+
Enter the starting principal, nominal annual interest rate, time in years, and the number of compounding periods per year.
Does this calculator include monthly deposits?+
No. This page calculates growth of one starting principal. Use the future value, SIP, or savings goal calculator for recurring contributions.
Is compound interest the same as APY?+
Not exactly. APY expresses the effective annual yield after compounding, while a nominal annual rate must be combined with its compounding frequency.
How does the Compound Interest Calculator calculate the result?+
For the Compound Interest Calculator, it uses the Compound interest formula: A = P x (1 + r / n)^(n x t). 10,000 at 8% compounded monthly for 5 years becomes 10,000 x (1 + 0.08 / 12)^60.
What information do I need to use the Compound Interest Calculator?+
Enter the starting principal, nominal annual interest rate, term in years, and compounding frequency. This calculator does not add recurring contributions or withdrawals.
How accurate is the Compound Interest Calculator?+
The result is exact for the principal, fixed nominal annual rate, term, and compounding frequency entered. Real balances can differ because of rate changes, contributions, withdrawals, fees, taxes, day-count rules, and rounding.
RelatedNearby finance calculators for the next step after Compound Interest Calculator.
Finance guide
How to use the Compound Interest Calculator
Project one starting principal with a fixed annual rate, term, and compounding frequency. Compare future value with interest earned, and use a recurring-contribution calculator when deposits continue over time.
- 1
Enter principal and rate
Use the starting balance and nominal annual percentage rate shown by the account or scenario.
- 2
Match time and frequency
Enter the term in years and select how often interest is compounded: daily, monthly, quarterly, or annually.
- 3
Separate growth from deposits
Read future value and interest earned for the starting principal only; use a recurring-payment calculator for additional deposits.