Interest Calculator

Modify the values and click the Calculate button to use

Final Balance: $54,535.20

Initial Investment: $20,000.00
Total Contributions: $45,000.00
Total Interest: $9,535.20
Term: 60 months

83% Contributions17% Interest

Accumulation schedule

Year	Date	Deposits	Interest	Ending balance
1	Nov 2027	$5,000.00	$1,250.00	$26,250.00
2	Nov 2028	$5,000.00	$1,562.50	$32,812.50
3	Nov 2029	$5,000.00	$1,890.62	$39,703.12
4	Nov 2030	$5,000.00	$2,235.16	$46,938.28
5	Nov 2031	$5,000.00	$2,596.91	$54,535.20

Balance, contributions, and interest over time

Balance
Interest
Contributions

What this interest calculator does

This calculator estimates how an initial balance, regular contributions, and compound interest grow over time. You can add money annually or monthly and choose whether contributions are made at the beginning or end of each period.

It does not include taxes, inflation, or fees. Continuous compounding and some less common compounding schedules are not included in this version.

How to use this calculator

Enter the initial investment.
Enter any annual or monthly contribution.
Choose when contributions are made.
Enter the annual interest rate and investment term.
Choose the compounding frequency.
Click Calculate to see the final balance and growth schedule.

Interest formula

For a lump sum with periodic compounding:

A = P × (1 + r / n)^(n × t)

P is the principal, r is the annual rate, n is the number of compounding periods per year, and t is the term in years.

Contributions are added at the selected timing. The calculator converts the compounding frequency to an effective monthly rate and simulates the balance month by month.

What the results include

Final balance: the estimated balance at the end of the term.
Total contributions: the initial investment plus all contributions.
Total interest: the final balance minus total contributions.
Annual growth schedule: yearly contributions, interest, and ending balance.
Growth chart: balance, cumulative contributions, and cumulative interest.

Frequently asked questions

Does this calculator include taxes?

No. Tax rates and tax-deferred accounts are not modeled in this version.

Does it adjust for inflation?

No. The result is a nominal balance. Inflation-adjusted value is not included.

What contribution timing should I use?

Use beginning-of-period timing if contributions are made at the start of the month or year. Use end-of-period timing if they are made at the end.

Source

References:

Disclaimer

This calculator is for informational and planning purposes only. It is not financial, tax, or investment advice. Actual account terms and returns may differ.

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