PERCENTAGE CHANGE VOLATILITY CALCULATOR

Measure how much a series of values fluctuates





This is a mathematical calculation only, not investment advice.


Enter a series of values in order (like daily closing prices) separated by commas. This calculator computes the percentage change from each value to the next, then measures how much those changes vary using the standard deviation — a common way to express volatility.

Volatility is defined as the standard deviation of daily percentage changes

Example
Daily prices: 100, 102, 99, 105, 103, 108
Daily changes: +2%, -2.94%, +6.06%, -1.90%, +4.85%
Average daily change: 1.61%. Volatility (standard deviation): about 3.44%.
A higher standard deviation means bigger day-to-day swings.



Example
Weekly closing prices: 50, 55, 48, 60
Changes: +10%, -12.73%, +25%
Average change: 7.42%. Volatility (standard deviation): about 15.6% — a wide spread, showing large week-to-week swings.

Example
Weekly closing prices: 50, 51, 49, 50
Changes: +2%, -3.92%, +2.04%
Average change: 0.04%. Volatility (standard deviation): about 2.7% — much steadier than the previous example.

When to use this calculator

Use this when you have a series of values over time and want to know how much they fluctuate, not just the overall change from first to last. For a single before/after comparison instead, use the stock price percentage change calculator.

Frequently asked questions

How many values do I need?
At least 3, so there are at least 2 daily (or period-to-period) changes to compare.

Does a higher volatility mean a worse investment?
Not necessarily — it means bigger swings in either direction. Volatility describes fluctuation, not overall direction or quality.

Can I use this for monthly or yearly data instead of daily?
Yes, just enter your values in order; the calculator treats each entry as one period, regardless of whether that period is a day, week, month, or year. Related: stock price percentage change calculator and daily vs monthly percentage change.