ReckonBoxHow the FD calculator works
A fixed deposit is a lump sum locked with a bank for a set term at a fixed rate, and a cumulative FD compounds that interest every quarter until it matures. This calculator takes your deposit, the rate and the tenure, then shows the maturity value, the interest earned, the monthly income if you pick a payout FD instead, and the interest left after TDS. The rate stays editable, so it fits any bank or the post office, whatever quote you have in hand.
On the default numbers the growth is steady. A Rs 1,00,000 deposit at 7% for 5 years matures to about Rs 1,41,478, so it earns Rs 41,478 of interest, all paid together at the end. Push the deposit to Rs 10,00,000 and the same rate returns about Rs 14,14,778.
The FD maturity formula
FD maturity for a cumulative deposit is the principal compounded quarterly at the rate, written as M = P times (1 + r/4) to the power of 4 times the years. Banks in India compound FD interest four times a year, so the exponent counts the quarters in the term. A Rs 2,00,000 deposit at 6.5% for 2 years gives 2,00,000 times 1.01625 to the power 8, which is Rs 2,27,528, matching the bank calculators.
Quarterly compounding is why an FD beats simple interest by a small margin. On the default certificate the quarterly method earns Rs 41,478 where plain simple interest would earn Rs 35,000, a difference of Rs 6,478 that comes purely from interest earning interest four times a year.
Cumulative or monthly payout
A cumulative FD reinvests the interest and pays the whole amount at maturity, while a monthly payout FD pays simple interest as income each month and returns only the principal at the end. The payout option gives you a regular cheque, but it gives up compounding, so it earns less overall. The comparison table above lays out all three modes for your own deposit.
| Option | What you receive | Interest on Rs 1,00,000 at 7% for 5 yr |
|---|---|---|
| Cumulative | Rs 1,41,478 at maturity | Rs 41,478 |
| Monthly payout | Rs 583 a month plus principal back | Rs 35,000 |
| Quarterly payout | Rs 1,750 a quarter plus principal back | Rs 35,000 |
The gap widens with the size and the term of the deposit, so for money you do not need as income, the cumulative option quietly wins.
How much monthly income an FD pays
A monthly payout FD pays the deposit times the annual rate divided by 12 each month, so Rs 1,00,000 at 7% pays about Rs 583 a month. Scale that up and the income scales with it: Rs 10,00,000 pays about Rs 5,833 a month, and Rs 20,00,000 pays about Rs 11,667. The principal is not touched and comes back in full when the FD matures.
This is the number behind searches like "1 lakh FD interest per month". It is simple interest, so unlike the cumulative maturity it does not grow, and the monthly figure is the same every month for the whole term.
Tax on FD interest, and TDS
FD interest is fully taxable at your income tax slab, and banks deduct 10% TDS once your annual FD interest crosses Rs 50,000, or Rs 1,00,000 for senior citizens, from FY2025-26. The general threshold rose from Rs 40,000 and the senior threshold from Rs 50,000 with effect from 1 April 2025. If you have not given your PAN the bank deducts 20%, and Form 15G or 15H stops the deduction when your total income is below the taxable limit.
On the default Rs 1,00,000 deposit the annual interest is only Rs 7,000, so no TDS applies. Raise the deposit to Rs 10,00,000 and the annual interest of Rs 70,000 crosses the general limit, so a general depositor sees about Rs 41,478 deducted across the term, while a senior citizen, with the Rs 1,00,000 limit, sees none. The calculator treats this as cashflow, since TDS is adjusted against your final tax, not an extra charge.
Senior citizens and the post office
Most banks add about 0.25% to 0.50% to the FD rate for depositors aged 60 and above, on top of the higher Rs 1,00,000 TDS-free limit. The uplift varies by bank, so enter your bank senior rate in the calculator and switch on the senior toggle to apply the higher tax-free limit. The SCSS calculator covers the dedicated senior citizen scheme, which pays more than a regular FD.
The post office time deposit is the same idea run by India Post, with tenures of 1, 2, 3 and 5 years and the same quarterly compounding, so this tool works for it once you enter the post office rate. The 5-year post office deposit also earns a Section 80C deduction, which a bank FD only matches through a separate 5-year tax-saving FD. For a steady monthly cheque, the POMIS calculator covers the post office monthly income scheme.
What this does not promise
FD rates are set by each bank and change often, so the maturity here reflects the rate you enter, not a live quote. The TDS figure is an estimate on the current thresholds and is adjusted against your total tax, so your real tax depends on your slab. Premature withdrawal reduces the rate by 0.5% to 1% and pays interest only for the period held, which this tool does not model. FD terms are set by the bank and the RBI, and this is not investment or tax advice, so a qualified adviser can confirm how a deposit fits your plans.
Frequently asked questions
What is an FD calculator? An FD calculator works out the maturity value and interest of a fixed deposit from your deposit, the interest rate and the tenure. It uses quarterly compounding, the Indian bank standard, so a Rs 1,00,000 FD at 7% for 5 years matures to about Rs 1,41,478.
How is FD maturity calculated? FD maturity for a cumulative deposit is M = P times (1 + r/4) to the power of 4 times the years, since banks compound interest quarterly. With P as the deposit, r the annual rate as a decimal and the exponent counting the quarters, a Rs 2,00,000 FD at 6.5% for 2 years matures to Rs 2,27,528.
What is the difference between a cumulative and a monthly payout FD? A cumulative FD reinvests the interest and compounds it quarterly, paying the whole amount at maturity, while a monthly payout FD pays simple interest as income each month and returns only the principal at the end. Because compounding is lost, the payout option earns less: Rs 1,00,000 at 7% for 5 years earns Rs 41,478 cumulative against Rs 35,000 as monthly payout.
How much monthly income does an FD pay? A monthly payout FD pays the deposit times the annual rate divided by 12 each month, so Rs 1,00,000 at 7% pays about Rs 583 a month, and Rs 10,00,000 pays about Rs 5,833 a month. The principal is returned separately when the FD matures.
Is FD interest taxable, and what is the TDS? FD interest is fully taxable at your income tax slab, and banks deduct 10% TDS once your annual FD interest crosses Rs 50,000, or Rs 1,00,000 for senior citizens, from FY2025-26. Without a PAN the TDS is 20%, and Form 15G or 15H stops it if your total income is below the taxable limit.
Do senior citizens get a higher FD rate? Most banks add about 0.25% to 0.50% to the FD rate for senior citizens aged 60 and above, and the TDS-free interest limit is higher at Rs 1,00,000 a year. The exact rate varies by bank, so enter your bank senior rate in the calculator.
What happens if I break an FD early? On a premature withdrawal, banks usually pay interest for the period actually held and reduce the applicable rate by 0.5% to 1% as a penalty. The exact reduced rate depends on the bank and the tenure, so the final amount is lower than the maturity value shown here.
Does the post office FD work the same way? The post office time deposit is a fixed deposit with tenures of 1, 2, 3 and 5 years, and it compounds quarterly like a bank FD, so this calculator works for it too once you enter the post office rate. The 5-year post office time deposit also qualifies for a Section 80C deduction.