Bollinger Bands Calculator
Compute upper, middle, and lower Bollinger Bands to measure volatility and price extremes
Bollinger Bands Calculator
About This Calculator
The Bollinger Bands Calculator computes the three bands developed by John Bollinger in the 1980s. It uses a simple moving average (SMA) as the middle band and adds/subtracts a multiple of the standard deviation to create the upper and lower bands, forming a dynamic volatility envelope around price.
How Bollinger Bands Are Calculated
- Middle Band: N-period Simple Moving Average (default: 20)
- Upper Band: Middle Band + (K × Standard Deviation) — default K=2
- Lower Band: Middle Band − (K × Standard Deviation) — default K=2
- Bandwidth: Measures how wide the bands are relative to the middle band
Key Trading Signals
- Bollinger Squeeze: Narrow bands signal low volatility and a potential breakout
- Price at Upper Band: Potentially overbought — watch for reversal
- Price at Lower Band: Potentially oversold — watch for bounce
- Price Walking the Band: Strong trend when price consistently touches one band