What is a Fixed Deposit?
A Fixed Deposit (FD) is India's most trusted savings instrument. You lock a lump sum with a bank or NBFC for a fixed period at a pre-agreed interest rate. Unlike a savings account, the rate doesn't fluctuate — what you're told at the time of deposit is what you get at maturity. This predictability makes FDs the default choice for conservative savers, emergency funds, and short-to-medium term goals.
India holds over ₹200 lakh crore in term deposits. The numbers don't lie — when markets feel uncertain, money flows into FDs.
The compound interest formula
FD maturity is calculated using the compound interest formula:
A = P × (1 + r/n)^(n×t)
Where:
- P = principal (deposit amount)
- r = annual interest rate as a decimal (e.g., 7% → 0.07)
- n = compounding periods per year (monthly=12, quarterly=4, half-yearly=2, yearly=1)
- t = tenure in years
Example: ₹5 lakh at 7% for 2 years, compounded quarterly:
- A = 5,00,000 × (1 + 0.07/4)^(4×2)
- A = 5,00,000 × (1.0175)^8
- A = 5,00,000 × 1.1489 ≈ ₹5,74,446
Interest earned = ₹74,446. All from doing nothing.
Compounding frequency matters more than you think
Four options, four outcomes. For ₹5L at 7% for 5 years:
| Compounding | Maturity | Interest | |---|---|---| | Yearly | ₹7,01,276 | ₹2,01,276 | | Half-yearly | ₹7,05,789 | ₹2,05,789 | | Quarterly | ₹7,08,108 | ₹2,08,108 | | Monthly | ₹7,09,601 | ₹2,09,601 |
Monthly vs yearly: ₹8,325 extra on ₹5L. That's real money — and you didn't do anything differently except choose the right bank.
Most Indian banks (SBI, HDFC, ICICI, Axis) compound FD interest quarterly. Some NBFCs and small finance banks offer monthly compounding. Check the fine print of your bank's FD scheme.
Effective Annual Yield — the true rate
The nominal rate (7%) and the effective yield differ once you add compounding. The Effective Annual Yield (EAY) formula:
EAY = (1 + r/n)^n − 1
For 7% compounded quarterly: EAY = (1.0175)^4 − 1 = 7.19%
This is the number to use when comparing FDs across banks. A 6.9% monthly-compounded FD has an EAY of 7.12%, which beats a 7% annually-compounded FD (EAY = 7.00%). Never compare FDs on nominal rate alone.
FD taxation — what you must know
FD interest is fully taxable as income — it is added to your total income and taxed at your applicable slab rate. This is unlike equity mutual funds (where long-term gains have lower rates) or PPF (where maturity is fully tax-free).
TDS rules:
- Banks deduct TDS at 10% if annual FD interest exceeds ₹40,000 (₹50,000 for senior citizens)
- TDS is deducted even if your interest accrues but hasn't been paid out
- If your income is below the taxable limit, submit Form 15G (or 15H for seniors over 60) to your bank to stop TDS deduction
Post-tax return calculation: If you earn ₹1L in FD interest and fall in the 20% tax bracket:
- Tax payable = ₹20,000
- Post-tax interest = ₹80,000
- Post-tax return = 5.6% (on a 7% pre-tax FD)
For high earners, this significantly reduces FD's attractiveness versus tax-free alternatives like PPF.
When FDs make sense — and when they don't
FD wins when:
- You need capital safety (zero market risk)
- Your time horizon is 1–3 years
- You want a guaranteed return for a specific goal (vacation, down payment)
- You're in a low tax bracket (5% or nil), making the tax drag small
FD loses when:
- Your time horizon is 5+ years (PPF at 7.1% tax-free, or equity SIPs, compound significantly better)
- You're in a 30% tax bracket (post-tax FD yield: 4.9% at 7% rate — below inflation)
- You need liquidity (premature FD withdrawal carries a 0.5–1% penalty)
FD vs PPF: the numbers
For ₹1.5L/year invested for 15 years:
- FD at 7% (30% tax bracket): Post-tax corpus ≈ ₹38L
- PPF at 7.1% (tax-free): Corpus ≈ ₹40.7L
PPF wins on corpus AND gives a tax deduction on contribution (Section 80C under old regime). The FD only makes sense when the PPF lock-in doesn't suit your timeline.
Choosing between bank types
| Bank type | FD rate range | Safety | |---|---|---| | Public sector (SBI, BoI) | 6.5–7% | Government guarantee | | Private sector (HDFC, Axis) | 7–7.5% | DICGC insured up to ₹5L | | Small finance banks (AU, ESAF) | 7.5–9% | DICGC insured up to ₹5L | | NBFC (Bajaj Finance, etc.) | 7.5–8.5% | No deposit insurance |
DICGC insures deposits up to ₹5 lakh per bank across all accounts. If you're depositing more, split across banks to stay fully insured. NBFCs offer the highest rates but carry higher risk — check their credit rating (AA or above is safe) before depositing.