This calculator works out the standard deviation, variance, and mean from your entered data points, using the sample standard deviation formula commonly applied to financial returns.
Enter up to five data points, and the calculator returns the mean, variance, and standard deviation, a foundational concept behind volatility measurement in trading.
This calculator is for educational purposes only and uses sample standard deviation (n-1). Not financial advice.
A high standard deviation means your data points (like prices or returns) are widely spread from the average, in trading, this generally indicates higher volatility, a low standard deviation means values cluster tightly around the mean, indicating lower volatility.
This calculator uses sample standard deviation, dividing by n-1 rather than n, which is the more commonly used convention for financial data since you're typically working with a sample of returns, not the entire population.
Bollinger Bands are calculated by adding and subtracting a multiple of standard deviation from a moving average, use this calculator to find your standard deviation first, then apply it in our dedicated Bollinger Bands Calculator.
Standard deviation with very few data points can be significantly skewed by a single unusual value, more data points generally produce a more statistically reliable and representative measure of genuine variability.
Standard deviation is the risk (denominator) component of the Sharpe Ratio formula, a lower standard deviation for the same return produces a higher, more favourable Sharpe Ratio, use our dedicated Sharpe Ratio Calculator to combine both.