Accumulated Interest Calculator
Accumulated interest calculator works out Future value and Total you put in from Starting amount, Annual interest rate and The rate above is. The default figures on this page give compound interest earned of 6,288.95; change any entry and the result, the working and the sources update together.
Your figures
Updates as you typeHow this is worked out
6 steps
- Rate per compounding period = 5% / 1 compounding annually (1 a year).
- Effective annual yield = (1 + r/n)^n - 1 = 5%.
- No recurring contributions, so the balance grows from the 10000 starting amount alone.
- Future value after 10 years = 16288.95, of which 6288.95 is compound interest on 10000 paid in.
- Interest accumulated = ending balance - everything paid in = 16288.95 - 10000 = 6288.95.
- At this yield the balance doubles every ln(2)/ln(1+i) = 14.21 years.
Year-by-year balancetable
| year | contributions | interest | balance |
|---|---|---|---|
| 1 | 0 | 500 | 10,500 |
| 2 | 0 | 525 | 11,025 |
| 3 | 0 | 551.25 | 11,576.25 |
| 4 | 0 | 578.81 | 12,155.06 |
| 5 | 0 | 607.75 | 12,762.82 |
| 6 | 0 | 638.14 | 13,400.96 |
| 7 | 0 | 670.05 | 14,071 |
| 8 | 0 | 703.55 | 14,774.55 |
| 9 | 0 | 738.73 | 15,513.28 |
| 10 | 0 | 775.66 | 16,288.95 |
Its 9 worked examples are re-run on every release, last on 15 September 2026. What changed
Sources and references
4 sources
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What the accumulated interest calculator calculates
Projects the future value of a lump sum plus recurring contributions under any compounding frequency, and splits the result into principal, contributions and compound interest.
How to use this accumulated interest calculator
Enter Starting amount, Annual interest rate, The rate above is and Time invested. Future value updates as you type. Change one figure at a time to see what drives the result.
How the result is worked out
Open “How this is worked out” beside the result for the step-by-step calculation behind Future value, Total you put in and Of which contributions.
The method follows Compound interest formula A = P(1 + r/n)^(nt), and the future value of an annuity FV = PMT[((1+i)^N - 1)/i], US Securities and Exchange Commission (Investor.gov) - Compound Interest Calculator, 12 CFR Part 1030 (Regulation DD), Appendix A - Annual Percentage Yield Calculation and Pag-IBIG Fund - Modified Pag-IBIG II (MP2) Savings Program.
What you can compare
Change one input at a time to see how it affects Future value, Total you put in and Of which contributions. The inputs you can vary are Starting amount, Annual interest rate, The rate above is, Time invested, Compounding frequency and Inflation rate.
Results are general information, not financial, tax, legal, medical or engineering advice. Check any decision that matters with a qualified professional.
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Frequently asked questions
How to calculate accumulated interest?
Projects the future value of a lump sum plus recurring contributions under any compounding frequency, and splits the result into principal, contributions and compound interest. Open “How this is worked out” beside the result to see each step for your own figures.
What is 5% interest on $50,000?
Projects the future value of a lump sum plus recurring contributions under any compounding frequency, and splits the result into principal, contributions and compound interest. On this page it is computed from Starting amount, Annual interest rate and The rate above is and shown as Future value, Total you put in and Of which contributions.
What information do I need for the accumulated interest calculator?
You need Starting amount, Annual interest rate, The rate above is, Time invested, Compounding frequency, Inflation rate and Tax rate on interest. The page opens with default figures that give compound interest earned of 6,288.95, so you can see the scale before entering your own.
What does this accumulated interest calculator show?
It shows Future value, Total you put in, Of which contributions, Compound interest earned, Effective annual yield (APY), Equivalent nominal annual rate, Multiple of what you put in and Balance after tax on interest, with the working and any warnings for your entries.
Can I check how the accumulated interest calculator result was calculated?
Yes. The “How this is worked out” section shows the calculation steps, and the sources section identifies the references used for the method.