"Should I start a SIP or put the money in an FD?" is one of the most common money questions in Indian households. The honest answer is that they do different jobs. A fixed deposit gives you a known return with very low risk. A SIP in a mutual fund gives you market-linked returns that can be higher over long periods but go up and down along the way. The right choice depends on when you need the money and how much uncertainty you can live with.
This guide explains how each return is calculated, works through examples, covers how both are taxed in India, and gives a simple way to decide which suits each of your goals.
This article is general information, not investment advice. Mutual fund investments are subject to market risks; past returns do not guarantee future returns.
What is an FD?
A fixed deposit is a lump sum you place with a bank, small finance bank or post office for a fixed period at an interest rate that is locked in when you open it. You know on day one exactly what you will get at maturity. Bank deposits are covered by DICGC insurance up to ₹5 lakh per depositor per bank, including principal and interest.
If you want to deposit monthly instead of a lump sum, the equivalent is a recurring deposit (RD): a fixed amount every month at a fixed rate for a fixed period.
How FD returns are calculated
Most banks compound FD interest quarterly. The maturity amount is:
A = P × (1 + r/4)^(4 × t)
where P is the deposit, r is the annual rate as a decimal and t is the number of years.
Example: ₹1,00,000 at 7% for 5 years, compounded quarterly, grows to about ₹1,41,478. The rate here is only an example; actual FD rates vary by bank, tenure and whether you are a senior citizen.
What is a SIP?
A systematic investment plan is a way of investing a fixed amount in a mutual fund at regular intervals, usually monthly. Each instalment buys units at that day's price (the NAV). When markets fall, the same amount buys more units; when they rise, it buys fewer. Over time this averages your purchase price, which is called rupee cost averaging.
A SIP is not a product in itself. Its risk and return depend entirely on the fund you choose: equity funds are the most volatile and have historically offered higher long-term growth; debt funds are steadier; hybrid funds sit in between.
How SIP returns are estimated
SIP calculators use the future value of a series of monthly investments:
FV = P × [((1 + i)^n − 1) ÷ i] × (1 + i)
where P is the monthly amount, i is the assumed monthly return (annual return ÷ 12) and n is the number of months.
The key word is assumed. Unlike an FD rate, a SIP return is not known in advance. The calculator only shows what would happen if the fund delivered that return smoothly, which real markets never do.
Side-by-side: ₹10,000 a month for 15 years
You invest ₹18 lakh in total. Here is what that could become under different assumptions:
| Option | Assumed annual return | Value after 15 years |
|---|---|---|
| Recurring deposit style saving | 7% (fixed, compounded quarterly) | about ₹31.8 lakh |
| SIP, conservative outcome | 8% | about ₹34.8 lakh |
| SIP, moderate outcome | 10% | about ₹41.8 lakh |
| SIP, strong outcome | 12% | about ₹50.5 lakh |
Over long periods, even small differences in return compound into large differences in the final amount. But the SIP numbers are possibilities, not promises. In some 15-year periods equity returns have been lower than these figures, and in any single year an equity fund can fall sharply. Banks also usually cap RD tenures at 10 years, so a 15-year RD would mean renewing.
Over shorter periods the gap narrows and the risk matters more. For 5 years, ₹10,000 a month at 7% in an RD reaches about ₹7.2 lakh, while a SIP at an assumed 12% would reach about ₹8.2 lakh. But over five years, a weak market at the end could leave the SIP below the RD.
How they are taxed
Tax can change the comparison considerably, so look at returns after tax. Rules below are for individuals as of FY 2025-26.
FD and RD
- Interest is added to your income and taxed at your slab rate, every year, whether you withdraw it or not.
- Banks deduct TDS of 10% if your interest from that bank exceeds ₹50,000 in a financial year (₹1,00,000 for senior citizens). If you do not provide your PAN, TDS is higher. If your total income is below the taxable limit, you can submit Form 15G (or 15H if you are a senior citizen) to avoid TDS.
- A 5-year tax-saver FD qualifies for the Section 80C deduction, but only under the old tax regime.
At a 30% slab rate plus cess, a 7% FD earns roughly 4.8% after tax.
Equity mutual funds (via SIP)
- Each SIP instalment is treated as a separate purchase, with its own holding period.
- Units held 12 months or less: short-term capital gains taxed at 20%.
- Units held more than 12 months: long-term capital gains taxed at 12.5% on gains above ₹1.25 lakh a year.
- You pay tax only when you sell (redeem), not every year.
For example, if the 15-year, 12% SIP above were redeemed in a single year, the gain of about ₹32.5 lakh would attract roughly ₹3.9 lakh of LTCG tax before cess. Redeeming gradually across years lets you use the ₹1.25 lakh exemption more than once.
ELSS funds, a type of equity fund with a 3-year lock-in, qualify for Section 80C under the old regime. Debt mutual fund units bought on or after 1 April 2023 are taxed at your slab rate regardless of holding period, which makes them closer to FDs for tax purposes.
How to choose: match the tool to the goal
The cleanest way to decide is by time horizon and how much certainty the goal needs.
- Emergency fund: FDs (or a liquid fund) that you can break quickly. Certainty and access matter more than return.
- Goals within 1 to 3 years, such as a wedding, a car or a home down payment: FDs and RDs, because there is not enough time to recover from a market fall.
- Goals 3 to 5 years away: a mix, or hybrid and debt funds, depending on how flexible the date is.
- Goals more than 7 years away, such as retirement or a child's higher education: equity SIPs have historically been a strong option because time smooths out volatility, ideally with a gradual shift to safer options as the goal gets close.
Many people do both: an FD ladder for safety and near-term goals, and SIPs for long-term wealth.
Common mistakes to avoid
- Comparing pre-tax FD returns with SIP returns. Always compare after tax.
- Treating the SIP calculator result as guaranteed. Run it at several return assumptions.
- Stopping a SIP when markets fall. Falls are when SIPs buy more units cheaply; stopping locks in the worst part of the cycle.
- Using equity SIPs for short-term goals. A market fall just before you need the money can derail the goal.
- Ignoring inflation. A 7% FD with 5% inflation grows your real purchasing power by only about 2% a year, before tax.
Run your own numbers
Advance Finance Calculator is our Android app for Indian personal finance. It includes SIP, SWP, FD, RD, PPF, CAGR, inflation, mutual fund and post office scheme calculators, and lets you save scenarios with different rates and tenures so you can compare them side by side, just like the tables above. If you are also paying off a loan, read how EMI is calculated to weigh prepaying against investing, and see our FY 2025-26 tax regime guide for how deductions like 80C fit in.
All figures here are illustrative and rounded. Check current rates with your bank and fund house, and consider speaking to a SEBI-registered investment adviser for personal advice.