What Is a Fixed Deposit (FD)?
A fixed deposit is a savings product in which you place a lump sum with a bank or another eligible institution for an agreed period, usually at a specified interest rate. The institution’s exact terms govern interest calculation, payout schedules, renewal and early withdrawal.
The RapidCalc FD Calculator helps estimate how your deposit could grow under a constant assumed interest rate. It supports both cumulative and periodic-payout illustrations.
How to Use the FD Calculator
- Enter the initial deposit amount.
- Enter the annual interest rate quoted for the deposit.
- Set the deposit tenure in years.
- Select Cumulative or Periodic payout.
- Select the compounding frequency or interest payout frequency.
- Review the maturity figure, total interest, chart and year-wise breakdown.
You can experiment with different amounts and rates to compare scenarios. Currency selection is only a display preference and does not exchange or convert funds.
FD Interest Calculation Formulas
Cumulative FD Formula
For interest compounded at regular intervals, the projected maturity value is:
A = P × (1 + r/n)^(n×t)
| Symbol | Meaning |
|---|---|
| A | Estimated maturity value |
| P | Principal deposited |
| r | Nominal annual interest rate as a decimal |
| n | Compounding periods per year |
| t | Deposit tenure in years |
Interest earned = A − P
The model supports annual (1), half-yearly (2), quarterly (4) and monthly (12) compounding. For fractional years, the calculator uses a smooth fractional-period projection; actual bank day-count and partial-period conventions can differ.
Non-Cumulative FD Payout Formula
For the calculator’s illustrative periodic-payout mode:
Interest per full payout period = P × r / n
Total estimated interest = P × r × t
Here, n is the number of payout periods per year. Interest is treated as paid out rather than reinvested, and the original principal is returned at maturity. Real banking products may discount monthly payouts or use different accrual and payment conventions.
Fixed Deposit Calculation Example
Suppose you invest ₹1,00,000 for 5 years at a 7% nominal annual rate with quarterly compounding.
| Detail | Value |
|---|---|
| Initial principal | ₹1,00,000.00 |
| Annual rate | 7% |
| Tenure | 5 years |
| Compounding | Quarterly |
| Number of periods | 20 |
| Estimated interest | ₹41,477.82 |
| Estimated maturity value | ₹1,41,477.82 |
The example assumes the same rate applies throughout the full term, with no withdrawals, fees or taxes.
Cumulative vs Non-Cumulative FD
| Feature | Cumulative FD | Periodic-payout FD |
|---|---|---|
| Interest | Reinvested and compounded | Paid at chosen intervals |
| Maturity payment | Principal plus accumulated interest | Principal, with interest already paid separately |
| Common objective | Growing a lump sum | Receiving regular income |
| Calculator model | Periodic compound-interest formula | Simple nominal-rate payouts without reinvestment |
A cumulative FD may produce a larger terminal maturity payment because interest remains invested. For periodic payouts, comparing the maturity payment alone overlooks the interest already received.
Monthly, Quarterly, Half-Yearly and Yearly Frequency
For cumulative FDs, frequency determines how often interest is added to the balance. For non-cumulative FDs, it determines how often estimated interest is paid. A payout frequency is not the same thing as compounding frequency.
At the same nominal rate, more frequent compounding generally increases a cumulative FD estimate. However, actual bank rates can differ by product, tenure, depositor category and payout choice.
What Affects FD Maturity Value?
Deposit Amount
A larger initial principal generally results in proportionally larger interest, all other assumptions unchanged.
Annual Interest Rate
Higher assumed rates increase projected interest. A rate entered in this calculator is not a current offer or guarantee.
Tenure
A longer tenure gives cumulative interest more time to compound, while periodic-payout models generate additional installments of interest.
Taxes and Early Withdrawal
Tax deducted at source (TDS), applicable income tax, early-withdrawal penalties and other product conditions can reduce the amount you retain. These are not deducted by this calculator.
How to Compare Fixed Deposit Offers
Compare the quoted rate, annual effective yield for cumulative FDs, tenure, interest-crediting or payout conventions, early-exit terms, renewal conditions, deposit-insurance eligibility and applicable taxes. Check the bank’s official product disclosure before making a deposit.
Related RapidCalc Calculators
- Compound Interest Calculator — Compare periodic compound-growth scenarios.
- PPF Calculator — Explore long-term PPF contributions and projected interest.
- RD Calculator — Estimate recurring deposit savings.
- SIP Calculator — Project monthly investment growth under an assumed return.
- Monthly Interest Calculator — Estimate monthly borrowing or lending interest.
Important Assumptions and Limitations
This tool provides an educational, fixed-rate illustration. It does not automatically incorporate taxes, TDS, revised rates, premature withdrawal, loan-against-FD arrangements, bank-specific day-count conventions, discounted monthly interest payouts or fees. Confirm actual deposit terms and rates with the relevant institution.