Compound Interest Calculator
Compound growth of a principal with optional regular contributions and any compounding frequency.
Inputs
Formula
- A = P × (1 + r/n)^(n·t)
- With contributions: A = P(1 + i)^N + PMT × [((1 + i)^N − 1) / i]
- i = r/12/100 for monthly contributions, N = 12t
- Compound interest = A − P − total contributions
Compounding pays interest on previously earned interest, so growth is exponential rather than linear. When regular contributions are added, the balance is the sum of two terms: the original principal compounding on its own, plus the future value of the contribution annuity.
Step-by-step calculation
- 1
Periodic rate
8% / 12
0.6667%
- 2
Principal growth
P(1 + r/n)^(n·t)
₹221,964
- 3
Contribution growth
no contributions
₹0
- 4
Final amount
sum of both
₹221,964
Assumptions
- Rate is constant
- Contributions occur at the end of each month
- No tax or fees deducted
Tips
- Frequency matters less than rate and time — doubling the horizon beats doubling the frequency.
- Compare products using the effective annual rate.
Warnings
- Advertised 'compounded daily' rates are usually nominal; convert to effective before comparing.
Standards & references
- Standard compound interest formula
- Effective annual rate convention
Frequently asked questions
What does the Compound Interest Calculator do?
Compound growth of a principal with optional regular contributions and any compounding frequency. The Compound Interest Calculator on OneCalcApp returns the result instantly as you type, together with the formula and the substituted values.
How do I use the Compound Interest Calculator?
Enter your values in the input fields, choose the relevant units or options, and the Compound Interest Calculator recalculates automatically. You can copy, print or export the result.
Is the Compound Interest Calculator free to use?
Yes. The Compound Interest Calculator is completely free, needs no sign-up and has no usage limit on OneCalcApp.
How accurate is the Compound Interest Calculator?
It uses the standard formula A = P × (1 + r/n)^(n·t) and full double-precision arithmetic, so results match a manual calculation to the displayed number of digits.
Does the Compound Interest Calculator work on mobile and offline?
Yes. The Compound Interest Calculator runs entirely in your browser on phones, tablets and desktops, and your inputs never leave your device.
Where can I find related tools?
OneCalcApp hosts 300+ calculators and converters, including the full Finance collection. Related tools are linked at the bottom of every page.
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