Geometric Mean Rate of Return Formula:
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The Geometric Mean Rate of Return (GM ROR) measures the average rate of return of an investment over multiple periods, accounting for compounding effects. It provides a more accurate representation of investment performance than simple arithmetic mean.
The calculator uses the geometric mean rate of return formula:
Where:
Explanation: The formula calculates the compound average growth rate by multiplying the growth factors (1 + return) for each period, taking the nth root, and subtracting 1 to get the average periodic return.
Details: Geometric mean is essential for investment analysis as it accurately reflects the compounded growth rate over time, unlike arithmetic mean which can overestimate returns due to volatility.
Tips: Enter period returns as comma-separated decimal values (e.g., 0.05 for 5%, -0.03 for -3%). Ensure all returns are valid numbers between -1 and positive infinity.
Q1: Why use geometric mean instead of arithmetic mean for returns?
A: Geometric mean accounts for compounding and volatility, providing the true average growth rate, while arithmetic mean can be misleading for volatile investments.
Q2: What's the difference between GM ROR and CAGR?
A: GM ROR and CAGR (Compound Annual Growth Rate) are essentially the same concept - both measure the geometric average return over multiple periods.
Q3: When should I use geometric mean rate of return?
A: Use it for analyzing investment performance over multiple periods, comparing different investment strategies, and calculating long-term average returns.
Q4: Can GM ROR be negative?
A: Yes, if the overall investment loses value over the measured periods, the geometric mean rate of return will be negative.
Q5: How does volatility affect GM ROR?
A: Higher volatility typically results in a lower geometric mean return compared to arithmetic mean, due to the compounding of losses.