- What Is an Expense Ratio?
- Fund A vs Fund B: Where the Gap Comes From
- Why does the gap keep growing?
- What This Means for a SIP Investor
- Where Expense Ratio Matters Most
- Things to Keep in Mind
- The Bottom Line
Two mutual funds. Same category. Same gross return of 12% per year. One charges 0.5% as its annual fee, the other charges 1.5%. The difference is just 1%. It sounds trivial.
Over 10 years, on a single ₹1 lakh investment, that 1% difference quietly erases over ₹25,000 from your corpus, without a single bad investment decision on your part.
This is the expense ratio at work.
What Is an Expense Ratio?
The expense ratio, also called Total Expense Ratio or TER, is the annual fee an Asset Management Company (AMC) charges to manage your money. It covers fund management, administration, and operational costs.
The important thing to understand is how it gets deducted. The expense ratio is deducted daily from the fund's NAV. This means investors never receive a separate bill, the return shown on their dashboard is already net of fees. If a fund earns 12% gross but charges 1.5%, the investor effectively earns 10.5%. The deduction happens silently, every single day, before the NAV is published.
This is why most investors never feel it, until they do the math over a long period.
Fund A vs Fund B: Where the Gap Comes From
Here is the core setup. Two funds, identical 12% gross return, different expense ratios:
| Fund A | Fund B | |
| Gross Return | 12% per year | 12% per year |
| Expense Ratio | 0.5% | 1.5% |
| Net Return to Investor | 11.5% | 10.5% |
Now invest ₹1,00,000 in each and leave it untouched. Here is what happens:
| Year | Fund A (11.5%) | Fund B (10.5%) | Gap |
| Year 1 | ₹1,11,500 | ₹1,10,500 | ₹1,000 |
| Year 2 | ₹1,24,322 | ₹1,22,102 | ₹2,220 |
| Year 3 | ₹1,38,620 | ₹1,34,923 | ₹3,696 |
| Year 5 | ₹1,72,335 | ₹1,64,745 | ₹7,591 |
| Year 7 | ₹2,14,252 | ₹2,01,157 | ₹13,094 |
| Year 10 | ₹2,96,995 | ₹2,71,408 | ₹25,587 |
In Year 1, the gap is just ₹1,000. By Year 10, it is ₹25,587, on the same ₹1 lakh, earning the same gross return.
Note: In real mutual funds, TER is deducted daily from NAV rather than being subtracted once per year. Therefore, the exact real-world difference would be slightly different, but for an educational illustration, the ₹25,587 figure is accurate.
Why does the gap keep growing?
Because each year, Fund B starts from a slightly lower base than Fund A. In Year 1, Fund B earns 10.5% on ₹1,00,000. In Year 2, it earns 10.5% on ₹1,10,500, while Fund A earns 11.5% on ₹1,11,500. The higher base of Fund A compounds at a higher rate every single year. The gap does not stay flat, it widens. This is the compounding drag of a higher expense ratio.
Think of it this way: the expense ratio does not just cut your return once. It reduces the base on which all future returns are calculated. Every rupee lost to fees in Year 1 is a rupee that does not compound in Year 2, Year 3, and beyond.
What This Means for a SIP Investor
Meera runs a ₹10,000 per month SIP. She is comparing two funds in the same category, same gross return of 12%, but Fund A is a Direct plan at 0.5% TER and Fund B is a Regular plan at 1.5% TER.
| Period | Total Invested | Fund A Corpus | Fund B Corpus | Difference |
| 5 Years | ₹6,00,000 | ₹8,13,572 | ₹7,91,555 | ₹22,016 |
| 7 Years | ₹8,40,000 | ₹12,93,819 | ₹12,43,732 | ₹50,087 |
| 10 Years | ₹12,00,000 | ₹22,55,442 | ₹21,26,594 | ₹1,28,848 |
Meera ends up with over ₹1.28 lakh more in Fund A at the end of 10 years. She did not pick better stocks. She did not time the market. She simply chose the lower expense ratio option of the same fund.
Where Expense Ratio Matters Most
Index funds and ETFs: Here the expense ratio is the single most important differentiator. Since every Nifty 50 index fund holds the same 50 stocks in the same proportion, the only variable is cost. The lowest TER Nifty 50 index funds in the Direct plan include options at 0.05% to 0.40%, a significant difference from actively managed funds charging 0.5% to 2%.
Active funds: A higher expense ratio can be justified here, but only if the fund consistently delivers returns above its benchmark after costs. The outperformance (called alpha) must exceed the extra fee being charged. If it does not, the higher TER is simply a drag.
Direct vs Regular plans: This is the most relevant comparison for most investors. SEBI introduced Direct Plans in 2013, allowing investors to bypass distributor commissions and invest at lower TERs. The TER difference between Direct and Regular plans is typically 0.5% to 1.5% per year. The underlying portfolio is identical, the only difference is the fee.
Things to Keep in Mind
- A lower expense ratio alone is not a reason to pick a fund. A fund with 0.5% TER and poor stock selection is worse than one with 1.2% TER and strong, consistent returns. Cost matters, but performance matters too.
- SEBI caps the Total Expense Ratio based on fund size; larger funds with higher AUM are required to charge lower TERs. This is why expense ratios of the same fund can change slightly over time.
- Always compare expense ratios within the same category. An equity fund at 1% and a debt fund at 0.5% are not directly comparable; the categories have different cost structures.
- Even a 1% TER can cost 10–20% of the final corpus over a 20-year investment horizon, purely due to the compounding effect. The longer the horizon, the bigger the impact.
The Bottom Line
The expense ratio is the one investment cost that is entirely within the investor's control at the point of fund selection. It requires no market prediction, no timing, no research into company fundamentals. It is a fixed, known drag, and choosing the lower-cost option between two otherwise comparable funds is one of the simplest decisions in investing.
Over one year, 1% feels invisible. Over ten years, it is over ₹25,000 on a single lakh, and over ₹1.28 lakh on a ₹10,000 monthly SIP. The compounding works both ways. The fee compounds against the investor just as surely as the returns compound in their favour.