Understanding NAV and units
How your investment turns into units, and why NAV movement is what drives your return.
A mutual fund doesn’t sell you shares at a fixed price the way a stock does — it sells you units, priced at the fund’s Net Asset Value (NAV) on the day you invest. Your actual return has nothing to do with how many units you ended up with or how “expensive” the NAV looked — it comes entirely from how much that NAV moved while you held it.
How your investment turns into units
₹1,00,000 invested at a NAV of ₹45.50 buys 2,197.80 units. Three years later, with the NAV at ₹68.20, those units are worth ₹1,49,890.11 — using the real computeMutualFundReturns formula (units = amount ÷ purchase NAV, value = units × current NAV), that’s a 49.89% absolute return, or 14.44% annualised.
Track a fund's absolute and annualised return over any holding period.
Why the NAV level itself doesn’t matter
A common instinct is to treat a fund’s NAV like a stock price — assuming a lower NAV means a “cheaper” fund with more room to grow, or that a higher NAV means an “expensive” one. Neither is true. The NAV level only determines how many units your rupees buy; it says nothing about the fund’s future growth.
The same ₹1,00,000, growing by the identical 49.89% over the identical 3 years, produces the exact same ₹1,49,890.11 final value and 14.44% annualised return regardless of the NAV level it started at — a fund starting at NAV ₹500 (buying only 200 units, ending at NAV ₹749.45) and a fund starting at NAV ₹10 (buying 10,000 units, ending at NAV ₹14.99) land on identical numbers to the ₹45.50-NAV example above. Three completely different unit counts, three completely different NAV levels, one identical return — because all three grew by the same percentage.
What actually drives your return
The only number that matters is the ratio between your purchase NAV and today’s NAV — everything else (how many units that bought, what the NAV’s absolute level is) is just arithmetic that falls out of it. Once that ratio is known, annualising it over your holding period is exactly the same problem as CAGR vs. absolute return — which is why computeMutualFundReturns hands the NAV ratio straight to the same CAGR formula once the unit-conversion step is done. Comparing two funds by their NAV level tells you nothing about which one performed better; comparing their NAV growth ratios over the same period does.
All figures are indicative and for educational purposes only — not financial advice.
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