FD vs Debt Fund vs Arbitrage Fund: After-Tax Returns

How the calculation works

1. FD interest is taxed every year at your slab rate and the after-tax interest is reinvested.
2. The debt fund grows untaxed and the gain is taxed at your slab rate when you redeem.
3. The arbitrage fund gain is taxed as an equity-oriented fund gain (short term or long term with the section 112A allowance).

Background and professional notes

Three returns are not three identical taxes

Fixed-deposit interest ordinarily enters taxable income annually on accrual or credited basis, while mutual-fund capital gains may be recognised on transfer or redemption. This model applies tax to the FD interest in each year and to the two fund scenarios upon exit. Using one post-tax CAGR formula for all three would ignore a substantial timing difference; the resulting gross returns and tax cash flows are therefore shown separately.

Debt-fund classification

Section 50AA introduced a special deemed short-term treatment for certain specified mutual funds, subject to acquisition date and fund composition. The relevant statutory definition changed from 1 April 2026. A long holding period alone does not automatically guarantee concessional long-term taxation. Enter a confirmed effective gain tax rate only after checking the actual scheme and acquisition date.

Arbitrage-fund classification

A fund marketed as arbitrage is not automatically eligible for equity-oriented tax rates. Eligibility depends on the relevant statutory fund classification, asset composition and securities transaction tax conditions. Eligible long-term gains under section 112A generally apply an aggregate annual threshold of ₹1.25 lakh, not a fresh allowance for every fund or transaction. Use the other-gains field to avoid counting the same threshold twice.

What the yield assumption means

The entered fund yields are assumed net of scheme management expenses but before investor tax and applicable exit charges. The tool does not forecast NAV or guarantee liquidity, returns, credit quality or taxation. If an exit load or redemption charge is material, adjust the return assumptions or use a detailed cash-flow model. Annual cash-flow reporting, TDS and distribution reinvestment are not all modelled.

Decision use

The comparison is most useful when you run realistic low, base and high yield scenarios and account for cash-flow needs, investment horizon and tax residence. An FD may have capital and deposit-insurance characteristics different from market-linked debt funds; avoid choosing only by the highest simulated CAGR.

Three-year worked comparison

Assume ₹10 lakh invested for three whole years, with hypothetical annual gross investment yields of 7% for an FD, 7.2% for a debt fund and 6.8% for an arbitrage fund. Assume an annual interest tax rate of 31.2% for the FD, a 31.2% tax on debt-fund exit gains, and a 12.5% exit tax on arbitrage gains without claiming Section 112A status or its allowance. The resulting purely illustrative proceeds are approximately ₹11,51,550, ₹11,59,565 and ₹11,90,913 respectively. The numbers are controlled by tax assumptions and timing, not evidence of future investment outperformance.

Tax-classification decision sequence

For an FD, determine how interest is credited, accrued and offered to tax in the relevant year, including TDS as a credit rather than an additional tax. For a debt-oriented mutual fund, establish acquisition date, composition and whether Section 50AA applies under the statutory definition relevant to the assessment period. For an arbitrage strategy, confirm whether the scheme satisfies equity-oriented conditions and whether the security transaction tax requirements apply. Then compute other eligible Section 112A gains already used against the aggregate ₹1.25 lakh threshold. Only after these checks should you select the applicable tax rate.

Risk and liquidity comparison

Deposit insurance limits and bank default risks differ from mutual fund NAV, market liquidity and scheme credit risks. A low-volatility arbitrage strategy is not a bank deposit and its realised return can change with futures premiums and fund flows. Debt instruments may be exposed to duration, credit, liquidity and taxation changes. The calculator ignores exit load, redemption charges, fund distributions, annual surcharge/cess mechanics and investment losses; adjust assumptions and retain the product factsheet before acting.

Assumptions and what this calculator does not cover

• Expected returns are your assumptions, not forecasts. The tax rates, the section 50AA treatment of the debt fund and the equity-fund classification must be checked for your units and purchase date.
• Expense ratios, exit loads and surcharge are not modelled beyond the returns you enter.
• The sample keeps the section 112A allowance off so that it matches the worked example. For an equity-oriented fund held over 12 months, set "Qualifies under Section 112A" to Yes to apply the Rs 1.25 lakh annual allowance.

Official sources and further reading

• Official source: Income Tax Department — Section 50AA
• Official source: Income Tax Department — Sale of Shares / 112A
• Official source: Income Tax Department — Capital Gains

Rates and rules were checked against these sources on 11 October 2026. Notifications and standards change; confirm on the official site before you file, book or advise.