Compound Interest CalculatorWith graph
Project how a lump sum and regular monthly investments can grow when returns are reinvested. Compare invested money with interest earned and test different compounding frequencies.
Highlights
- Includes both a starting amount and monthly contributions.
- Yearly, half-yearly, quarterly, monthly and daily compounding.
- Shows nominal rate, effective annual rate and wealth multiple.
- Interactive chart separates invested money from growth.
Everything is calculated in your browser. Nothing you enter is sent to a server or stored.
Future value
₹12.95 L
₹12,94,929
Total invested
₹7.00 L
Interest earned
₹5.95 L
Effective annual rate
10.47%
10% nominal rate
Wealth multiple
1.85×
Compounding over time
Compare the money you put in with the total value created by compounding.
How compounding builds wealth
Compounding means each period's return is added to the balance and can earn a return in later periods. Time matters twice: it gives you more contribution periods and more opportunities for earlier returns to compound.
A higher compounding frequency slightly raises the effective annual rate when the nominal rate is unchanged. The difference between monthly and daily compounding is usually small; contribution size, time and the underlying return matter much more.
Read the result realistically
The chart is a mathematical projection, not a forecast. Market-linked investments rarely deliver the same return every month, and the order of gains and losses affects what an investor experiences along the way.
Methodology
- The selected nominal annual rate is converted into an equivalent monthly rate for monthly cash flows.
- The opening balance earns interest each month and the monthly contribution is added at month-end.
- Effective annual rate reflects the selected compounding frequency, not investment fees or taxes.
Scope and assumptions
- The rate stays constant; real investments can fluctuate and do not grow smoothly.
- Monthly contributions are made at the end of each month.
- Fees, taxes, inflation and withdrawals are excluded.
FAQ
What is compound interest?
Compound interest is interest earned on the original principal plus interest already added to the balance. This interest-on-interest effect makes growth accelerate over long periods.
What is the compound interest formula?
For a lump sum, future value is P × (1 + r/n)^(n×t), where P is principal, r is the annual nominal rate, n is compounding periods per year and t is years. Monthly contributions require a future-value series in addition to the lump sum.
How does monthly compounding differ from annual compounding?
Monthly compounding credits interest 12 times a year, so each credit can earn interest sooner. At the same nominal rate it produces a slightly higher effective annual return than annual compounding.
Are monthly investments added at the start or end of the month?
This calculator adds them at month-end. Contributions made at the beginning of every month would finish slightly higher because each deposit compounds for one extra month.
Does this calculator account for inflation or tax?
No. It shows nominal pre-tax growth. For a real-world plan, reduce the expected return for fees and tax, then compare the result with future costs after inflation.