Geometric Mean Calculator

What is the Geometric Mean Calculator?

Calculate the geometric mean of positive numbers — ideal for growth rates. The geometric mean multiplies values and takes the root, which makes it the right average for growth rates and anything that compounds.

How to use the Geometric Mean Calculator

1. Paste or type your numbers into the box (a sample is pre-filled so you can see how it works).
2. Results update automatically as you type; you can also press Calculate.
3. Read the output: geometric mean, arithmetic mean.
4. Use the 📊 chart to see the result visually, then copy or share it.

Formula and method

Worked example

With the sample input, the Geometric Mean Calculator returns geometric mean: 1.05353920833; arithmetic mean: 1.055.

Where the Geometric Mean Calculator helps in real life

Your investment grew 10% one year, fell 5% the next and grew 8% the year after. Entering the growth factors 1.10, 0.95 and 1.08 gives the steady annual rate that would end at the same balance.

A biologist tracks a bacterial culture that multiplies by different factors each hour. The geometric mean gives the typical hourly growth factor across the whole experiment.

Common mistakes to avoid

• Averaging percentage returns arithmetically, which overstates growth.
• Including a zero or negative value, which the geometric mean cannot handle.
• Entering 10 for a 10% gain instead of the factor 1.10.
• Treating the result as a percentage without subtracting 1.

💡 Practical tip: Because returns compound, a +50% year followed by a −50% year leaves you down 25% — the geometric mean shows that, the arithmetic mean does not.

Tips for better results

• Convert each percentage change into a growth factor before entering it.
• Subtract 1 from the result and multiply by 100 to read it as a percentage.
• Compare with the arithmetic mean to see how much volatility costs you.

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