Key takeaways
- The correct formula is Real Post-Tax Return = ((1 + Nominal × (1 − Marginal Tax Rate)) / (1 + Inflation)) − 1. The shortcut Real ≈ Nominal − Inflation is an approximation that under-states the real loss at high tax rates.
- At a 7% FD yield, 30% slab, and 5.5% CPI inflation, the real post-tax return is approximately −0.6%. At the 39% effective HNI slab, the same FD produces roughly −1.2%.
- The April 2023 amendment removed indexation on debt mutual funds. Debt MFs and FDs now produce nearly identical real post-tax returns for HNIs — a regime change that re-ranks the entire fixed-income shelf.
- Surcharge on long-term capital gains is capped at 15% regardless of income, while surcharge on interest income is not. This creates a structural gap: at the top slab, equity LTCG is taxed at roughly 15% effective, while interest is taxed at roughly 39%.
- NRIs holding rupee deposits should add a fourth layer — currency depreciation. The INR has depreciated approximately 3% per year against the USD over the past decade. A "tax-free" NRE FD can still produce a negative real return in dollars.
What is the real return formula?
The real return formula is Real Return = ((1 + Nominal Return) / (1 + Inflation)) − 1. This is the Fisher equation, formalised by economist Irving Fisher in 1930. It tells you what your money is actually worth after inflation has done its work — what your wealth can buy, not what the bank statement claims it adds up to.
The shortcut you usually see in finance textbooks and online calculators is even simpler: Real Return ≈ Nominal Return − Inflation. That approximation is close enough at low rates. It is wrong by a meaningful amount at the rates Indian investors actually live with — where a 7% deposit and 5.5% inflation are not unusual at the same time.
For Indian investors, the more important problem is that even the correct Fisher formula is incomplete. It does not include tax. And tax, on most Indian investments, is the largest single deduction on returns — larger than fund fees, larger than transaction costs, sometimes larger than the headline yield itself. The version of the formula every Indian investor should use is:
Three layers, in this order. The nominal yield is what the product advertises. The tax layer is what the income tax department deducts. The inflation layer is what time deducts. Most Indian investors and many advisors apply only one or two of these. The third layer — usually tax — is where the real damage happens.
Why subtraction is wrong at these rates
If a 7% nominal return and 5.5% inflation gave a 1.5% real return, the world would be kinder than it is. The Fisher equation is more honest. Plug the numbers in: (1.07 / 1.055) − 1 = 1.42%. That is the real return before tax. Smaller than the subtraction implies, but still positive.
Now apply the tax layer. At a 30% slab, the post-tax return is 7% × 0.70 = 4.90%. Apply Fisher to that: (1.049 / 1.055) − 1 = −0.57%. The deposit grows in nominal rupees every year. The basket of goods those rupees can buy shrinks slightly. Both are true at the same time.
The same 7% nominal yield produces four different real returns
The product advertises a number. The tax department applies a different rate depending on what wrapper the number sits inside. Inflation does the rest. The table below shows four common Indian instruments, all priced near the same nominal yield, and what each produces for an HNI in the highest effective tax slab.
| Instrument | Nominal yield | Tax treatment | Real post-tax (39% slab, 5.5% CPI) |
|---|---|---|---|
| Fixed deposit (1-yr) | 7.00% | Slab — 39% effective | −1.16% |
| Debt MF (post-Apr 2023) | 7.50% | Slab — 39% effective | −0.87% |
| Arbitrage fund (LTCG) | 6.00% | Equity — ~15% effective | −0.38% |
| Equity MF (long-term avg) | 12.00% | Equity — ~15% effective | +4.46% |
All figures indicative. Nominal yields reflect typical May 2026 ranges; actual yields vary by issuer and tenure. Equity long-term return based on Nifty 500 historical average; year-to-year returns can be sharply higher or lower. CPI inflation assumed at 5.5% (RBI tolerance band midpoint). Surcharge on capital gains capped at 15%; surcharge on interest income up to 25%.
Three of the four produce a negative real return. The fourth does not — but the fourth is also the one that can fall 25% in a bad year before it makes its long-term average. The table is not a recommendation. It is an inventory of what each product is and is not doing for you, after the layers are applied.
April 2023: the day the formula quietly changed for debt funds
For two decades, debt mutual funds had a structural advantage that fixed deposits did not. Held for more than three years, gains were taxed at 20% with indexation — the cost of acquisition was inflated by the official cost inflation index, which usually reduced the taxable gain to a fraction of the actual gain. Many HNIs paid effective tax rates of 4–6% on long-term debt fund gains. FDs, taxed at slab, paid 30% on every rupee of interest.
That was the gap that made debt mutual funds the natural fixed-income choice for high-tax-bracket investors.
The Finance Bill 2023 amendment, applicable to debt fund purchases on or after 1 April 2023, removed both indexation and the special LTCG rate. Debt fund gains are now taxed at the investor's slab rate, no matter how long the units are held. The structural advantage that made debt mutual funds preferable to FDs for HNIs was eliminated overnight.
Much of the product literature still describes debt MFs the way they were positioned before the change — with general references to tax efficiency and credit quality. The numbers no longer support that framing for an HNI in the top slab. Debt funds may still earn marginally higher coupons than FDs, but the post-tax differential is small enough that the choice between them now turns on liquidity and credit risk, not tax. The real-return formula updated; the framing in many brochures did not.
The HNI surcharge math creates a 24-percentage-point gap nobody talks about
For investors with taxable income above ₹5 crore, the highest effective rate on income is approximately 39%: a 30% base rate, plus a 25% surcharge, plus a 4% cess. Most HNIs and their advisors know this number. Fewer notice that the surcharge on long-term capital gains is capped at 15%, regardless of income. The cap was put in to encourage long-term investing in capital assets. The result is a structural arbitrage.
| Income type | Base rate | Max surcharge | Effective rate (top slab) |
|---|---|---|---|
| Interest (FDs, debt MFs) | 30% | 25% | ~39% |
| Short-term capital gain (equity) | 20% | 15% (capped) | ~24% |
| Long-term capital gain (equity) | 12.5% | 15% (capped) | ~15% |
Effective rates rounded; actual rates include 4% health and education cess on the sum of base tax and surcharge. The ₹1.25 lakh annual exemption on equity LTCG further reduces the effective rate for most retail investors.
For an HNI in the top slab, a rupee of interest income is taxed at 39%. A rupee of long-term capital gain on equity is taxed at roughly 15%. That is a 24-percentage-point gap on the same rupee of pre-tax return. Apply it to the real-return formula and the asset-class ranking changes shape entirely.
This is the single most consequential piece of math for Indian HNI portfolio construction in 2026, and the one that gets the least airtime in product brochures. It is also the reason arbitrage funds — yielding 5.5–6.5% nominal, taxed as equity — frequently produce a higher real post-tax return than a 7% FD for an HNI, despite the lower headline. The same logic underpins newer SEBI categories that benefit from equity taxation; we wrote separately about how Specialized Investment Funds (SIFs) inherit this tax structure.
NRIs need a fourth layer: the currency drag
For an NRI whose home currency is the dollar or the dirham, the real-return formula has one more layer. The rupee's spending power matters less than what the deposit converts to in the home currency on the day the NRI needs the money. The INR has depreciated against the USD by approximately 3% per year over the past decade. Over a five-year horizon, that compounds.
An NRE FD at 7% looks tax-free in India — and it is, on the interest income. But a USD-based NRI who deposits ₹100 today and withdraws ₹140 five years later still has to convert that back to dollars at a rate that has moved against them. Strip out 3% per year of currency drag, and the 7% rupee yield becomes roughly 4% in dollar terms before US inflation. After 2% US inflation, the real USD return is around 2%.
That is not a disaster. It is also not what the rupee-yield brochure suggests. Tax-free in India is not the same as tax-free of currency loss. For NRIs, the formula must include the depreciation expectation, not just the income tax exemption. Many NRIs hold rupee deposits because they intend to spend in rupees eventually — for them, the rupee real return is the right number. For NRIs who plan to spend in their home currency, the dollar real return is the right number. The formula has to follow the wallet. (We cover the cross-border architecture of NRI wealth in detail on the global investing page.)
What survives the formula in 2026
At 5.5% inflation and the 39% HNI tax slab, the products that consistently produce positive real post-tax returns are narrow:
Equity-taxed instruments held long-term. Direct equity, equity mutual funds, equity-oriented hybrid funds, and arbitrage funds all benefit from the 12.5% LTCG rate with surcharge capped at 15%. The challenge is volatility — a 12% long-term average comes with 25% drawdowns along the way. The formula favours equity; temperament does not always cooperate.
Sovereign Gold Bonds held to maturity. The 2.5% coupon is taxed at slab, but capital appreciation at maturity is exempt from capital gains tax. If gold returns its long-term INR average over the holding period, SGBs can produce real post-tax returns above 5%. The trade-off is liquidity and the price-volatility of gold itself. (For a fuller comparison of how to own gold in 2026 — SGBs, ETFs, EGRs, and physical — see our gold ownership guide.)
Real estate (operationally). Rental yield plus capital appreciation, with indexation still available on long-term capital gains for property held over 24 months. Real returns are highly local and entirely illiquid. The formula gives you a number; the asset gives you a building.
The list is short on purpose. At current inflation and tax rates, most of the fixed-income products described as "stable" produce slightly negative real post-tax returns. That does not mean abandoning them — fixed income earns its place in a portfolio for liquidity, capital protection, and rebalancing optionality, not for real returns. It does mean naming honestly what each part of the portfolio is doing.
A five-step process to compute your portfolio's real post-tax return
Run this once a year. The numbers tell a different story than the statement.
Most HNIs running this calculation for the first time discover their portfolio's real post-tax return is in the 1–3% range — well below what the nominal numbers suggest, and well below the wealth-growth narrative most clients carry in their head. The exercise is uncomfortable. It is also necessary.
Real return is the only return
Nominal return is a story we tell ourselves at the bank counter. The number on the deposit slip moves up every year, and it feels like progress. Real return is what shows up at the supermarket five years later, after the tax department has taken its share and inflation has done its quiet work.
The formula is simple: subtract tax, divide by inflation, read the number that comes out. The implications are not. The rankings of "safe" and "risky" change once you apply it correctly. The April 2023 amendment changed them again. The 15% surcharge cap on capital gains created a structural gap most product literature still pretends does not exist.
The right response is not to panic-sell every fixed deposit. Fixed income earns its place for reasons beyond real return: liquidity, sleep at night, the ability to rebalance into equity when equity falls. The right response is to know which part of the portfolio is producing real wealth and which part is doing a different job, and to stop confusing the two.
Run the formula on your own statement. The number that comes out is the only one that matters.
Frequently asked questions about real return calculations in India
What is the real return formula in India?
The real return formula is Real Return = ((1 + Nominal Return) / (1 + Inflation)) − 1, also known as the Fisher equation. For Indian investors, the more useful formula adds a tax layer: Real Post-Tax Return = ((1 + Nominal Return × (1 − Marginal Tax Rate)) / (1 + Inflation)) − 1. The shortcut Real ≈ Nominal − Inflation is an approximation that under-states the real loss at high tax rates.
How do I calculate post-tax post-inflation return?
Three steps: First, multiply the nominal return by (1 − your marginal tax rate). Second, divide (1 + that post-tax return) by (1 + the inflation rate). Third, subtract 1. Example: a 7% FD at the 30% slab and 5.5% CPI inflation gives a real post-tax return of (1.049 / 1.055) − 1 = −0.57%.
Is my fixed deposit beating inflation in 2026?
For most Indian HNIs in 2026, no. At a 7% FD yield, 5.5% CPI inflation, and a 30% tax slab, the real post-tax return is approximately −0.6%. At the 39% effective HNI slab (with surcharge), the real return falls to roughly −1.2%. The deposit grows in nominal rupees every year, but the basket of goods those rupees can buy shrinks slightly.
What changed for debt mutual funds in April 2023?
The April 2023 Finance Bill amendment removed indexation benefit and the 20% LTCG rate on debt mutual funds purchased on or after 1 April 2023. Gains on these funds are now taxed at the investor's slab rate, regardless of holding period. The change put debt funds and fixed deposits on nearly identical post-tax footing for HNIs — a regime change that re-ranks the entire fixed-income shelf.
Which investments give positive real return after tax for HNIs in India?
At the 39% effective HNI tax slab and 5.5% CPI inflation, instruments commonly producing positive real post-tax returns include equity mutual funds (LTCG taxed at 12.5% beyond the ₹1.25 lakh exemption), arbitrage funds (taxed as equity), Sovereign Gold Bonds held to maturity (capital appreciation tax-free), and real estate held long-term (still eligible for indexation). Most fixed-income instruments — including FDs and post-2023 debt mutual funds — produce slightly negative real post-tax returns at current inflation.
What is the Fisher equation?
The Fisher equation, formalised by economist Irving Fisher in 1930, states that (1 + Nominal Return) = (1 + Real Return) × (1 + Inflation Rate). Rearranged: Real Return = ((1 + Nominal) / (1 + Inflation)) − 1. The simple subtraction Real ≈ Nominal − Inflation is an approximation that becomes inaccurate when either rate is high — a meaningful gap in Indian conditions, where both nominal yields and inflation often run above 5%.
Do NRIs need to factor in rupee depreciation when calculating real return?
Yes. An NRI whose home currency is USD or AED needs a fourth layer in the formula: currency drag. The INR has depreciated approximately 3% per year against the USD over the past decade. A 7% NRE FD looks tax-free in rupees but produces close to 4% in USD terms — and after US inflation of roughly 2%, the real USD return is around 2%. Tax-free in India does not mean tax-free of currency loss.
Are arbitrage funds tax efficient for HNIs in India?
Arbitrage funds receive equity-fund taxation in India because they maintain a minimum 65% equity allocation on a quarterly average basis. Gains held over 12 months are taxed at 12.5% LTCG (with surcharge capped at 15% on capital gains regardless of income). For an HNI in the 39% income slab, an arbitrage fund yielding 6% nominal can produce a higher post-tax return than a 7% FD, despite the lower headline yield.
Can a safe investment have a negative real return?
Yes. An investment can be safe in nominal terms — guaranteed not to lose principal in rupees — while still producing a negative real return. A fixed deposit at 7% nominal yield, taxed at slab rate, does not lose rupees. But after 5.5% inflation and the tax deduction, the rupees it pays out buy less than the original capital would have. Nominal safety and real safety are different things.
How does the 39% surcharge slab change my real return calculation?
For investors with taxable income above ₹5 crore, the highest effective rate is approximately 39% (30% base × 1.25 surcharge × 1.04 cess). Crucially, surcharge on long-term capital gains is capped at 15% regardless of income. This creates a structural gap: interest income from FDs and post-2023 debt funds is taxed at 39%, while equity LTCG is taxed at approximately 15% effective. The same nominal yield produces dramatically different real returns depending on which tax bucket applies.
What inflation rate should I use in the real return formula?
Use CPI (Consumer Price Index), not WPI (Wholesale Price Index), because CPI more closely reflects household spending. As of mid-2026, CPI is running near 5.5%, within the RBI's 4–6% tolerance band. For long-horizon planning, the RBI target midpoint of 5% is a reasonable assumption. For households whose spending is concentrated in education, healthcare, or imported goods, the effective personal inflation rate is often higher than headline CPI.
If you would like to run the real-return formula across your family's portfolio — and identify which holdings are doing the work the statement implies — we are here.
Start a conversationDisclaimer: This article is for informational purposes only and does not constitute investment advice, a recommendation, or an offer to buy or sell any securities. All yields, tax rates, inflation figures, and worked examples are indicative as of May 2026 and may change. Tax laws and surcharge structures change with each Finance Bill; please confirm applicable rates with a qualified tax professional. Past performance is not indicative of future results. Investments in mutual funds, equities, gold, and real estate are subject to market and liquidity risk; please read all scheme-related and product documents carefully before investing. Accrue Finvisor (ARN-162637) is a SEBI-registered mutual fund and investment distributor — not a SEBI-registered investment adviser — and does not provide personalised investment advice. For personalised advice, please consult a SEBI-registered investment adviser. Mutual fund investments are subject to market risks.