How the FD & RD calculator works
Fixed Deposits (FD) and Recurring Deposits (RD) are the two most common bank-deposit products in India. They sit at the conservative end of the risk spectrum: zero market exposure, returns guaranteed at the rate contracted on the day of opening, deposit insurance up to ₹5 lakh per depositor per bank under DICGC. The compute math is the easy part; the nuance is in compounding frequency, senior citizen bonuses, and the TDS that banks deduct on the interest you earn.
Fixed Deposit math
Most Indian banks compound FD interest quarterly. The maturity formula is the standard compound interest equation:
A = P × (1 + r/n)n × t
where P is the principal, r is the annual interest rate as a decimal, n is the number of compounding periods per year (typically 4 for quarterly, 12 for monthly, 1 for annual), and t is the tenure in years. The calculator also supports simple interest for the rare FD product that uses it (some short-term sweep-in linked deposits).
Worked example: ₹1 lakh at 7% for 5 years quarterly compounded gives roughly ₹1,41,478 at maturity—₹41,478 of interest earned over the term. Switching to monthly compounding nudges this to about ₹1,41,763; switching to annual drops it to ₹1,40,255.
Recurring Deposit math
RDs deposit a fixed amount every month and compound the running balance quarterly (the universal Indian convention). Banks publish maturity values via this closed form:
M = R × [(1 + i)Q − 1] / [1 − (1 + i)−1/3]
where R is the monthly deposit, i is the quarterly rate (annual / 4), and Q is the number of quarters (tenure / 3 months). The denominator captures the within-quarter convention: each month’s contribution earns proportional simple interest until the end of its quarter, then compounds with the running balance.
Worked example: ₹5,000 per month at 7% for 5 years gives roughly ₹3,58,950 at maturity—₹2,98,950 of which you put in, ₹59,950 of which the bank credits as interest. Tenures must be a multiple of 3 months at most banks; the calculator allows any value but real-world RDs are typically 6, 9, 12, 24, 36, 60, 84, or 120 months.
Senior citizen bonus
Every Indian bank pays an additional 0.5% on FDs and RDs to depositors aged 60 and above (some banks pay 0.75% on five-year tax-saver FDs to super-seniors). The calculator’s “Senior citizen” toggle adds this bonus to the contracted rate before any other calculation runs. The senior also gets a higher TDS-free threshold (₹50,000 vs ₹40,000 for non-seniors).
TDS under Section 194A
Banks deduct Tax Deducted at Source (TDS) on interest credited to your deposit account when the annual interest from that bank crosses the threshold:
- Below 60 years — TDS-free up to ₹40,000 of annual interest, then 10% TDS (with PAN), 20% (without PAN).
- Senior citizens (60+) — TDS-free up to ₹50,000, then 10% / 20% as above.
TDS is not the final tax—it is an advance towards your actual liability. The interest income still appears under “Income from Other Sources” in your ITR, taxed at your slab rate, with the TDS already paid credited against it. If your total income is below the basic exemption you can submit Form 15G (non-senior) or 15H (senior) to your bank and receive interest gross of TDS.
The calculator’s “Apply TDS” toggle simulates what actually credits to your account. Toggle it off to see the gross maturity, which is what you actually owe the IT Department on (slab rate, less TDS already paid).
Premature withdrawal penalty
If you break an FD before maturity, banks typically:
- Re-rate the deposit to the rate that would have appliedfor the actual tenure held (e.g., a 5-year FD broken at 2 years gets the 2-year rate, which is usually lower than the 5-year rate).
- Deduct a penalty of 0.5% to 1% from that re-rated rate.
The calculator models the penalty step explicitly. The “re-rate to actual tenure” step is a function of the bank’s rate card on the day of opening; we leave it to the user to enter the rate that actually applies to their actual holding period.
Tax-saver FD (Section 80C)
A 5-year tax-saver FD qualifies for Section 80C deduction up to ₹1.5 lakh. The principal locks for the full 5 years (no premature break allowed). Interest is fully taxable at your slab rate—there is no exemption on the interest itself, only on the principal investment. The calculator’s “Apply TDS” toggle still applies.
NRE vs NRO FD
For non-resident Indians, the choice between an NRE (Non-Resident External) and NRO (Non-Resident Ordinary) account materially changes tax treatment:
- NRE FD — Interest is fully exempt from income tax in India. Funds are repatriable. Currency: INR (deposit made from foreign earnings).
- NRO FD — Interest is taxable in India at slab rate (TDS deducted at 30% + surcharge + cess by default). Repatriation capped at USD 1 million per FY.
This calculator models a resident FD; for NRE/NRO computations you need to layer the residency-specific tax treatment on top.
Compounding frequency comparison
For a ₹1 lakh, 5-year FD at 7%:
- Annual: ₹1,40,255
- Half-yearly: ₹1,41,060
- Quarterly: ₹1,41,478 (PSU bank default)
- Monthly: ₹1,41,763
The headline rate is the same; only the compounding frequency differs. Most depositors don’t realise their bank’s compounding frequency is negotiable on bulk deposits—always ask for monthly.
Frequently asked questions
- Is my FD safe? What about deposit insurance?
- DICGC insures bank deposits (savings, current, FD, RD combined) up to ₹5 lakh per depositor per bank. If a bank fails, you receive up to ₹5 lakh within 90 days. Spreading deposits across multiple banks raises your effective cover.
- FD or RD — which earns more?
- For the same total invested over the same tenure, an FD always earns more because the entire principal earns interest from day one. An RD has the same total invested at the end but the deposits trickle in monthly, so the earlier deposits earn more interest than the later ones. RDs are useful for forced savings; FDs are better for capital that is already in hand.
- Why do small finance banks offer 8–9%?
- Small Finance Banks (SFBs) and some private NBFCs offer higher rates because their cost of capital is higher and they need to compete with mainstream banks for deposits. They are still DICGC-insured up to ₹5 lakh per depositor. Rates above 8% on longer tenors deserve a closer look at the bank’s capital adequacy ratio (CAR) and gross NPA.
- How accurate is this calculator?
- Every result is computed with high-precision decimal arithmetic and cross-checked against the SBI / HDFC / ICICI / Axis published FD and RD calculators. Eighteen real-world fixture rows and 1,000+ property-based assertions run on every commit.
Sources
- Reserve Bank of India Master Directions on FDs (
rbi.org.in) - Section 194A, Income Tax Act 1961 (TDS on interest)
- SBI / HDFC / ICICI / Axis published FD and RD rate cards
- DICGC deposit insurance scheme (₹5L cap)
Disclaimer. Bank deposit rates change frequently. Always verify the rate card on the bank’s website before opening a deposit. Tax treatment depends on your individual residency and income profile—consult a Chartered Accountant for binding tax guidance.