How to Use the RSI Overbought/Oversold Calculator
RSI (Relative Strength Index) is a momentum indicator that turns the ratio of average gains to average losses over a lookback period into a number between 0 and 100. Enter the average gain and average loss, and this tool instantly calculates the RSI value and a reference signal.
An RSI above 70 is generally read as overbought — buying pressure may be excessive in the short term — while below 30 signals oversold conditions. In strong trending markets, though, RSI can hover near these extremes for a long time, so it's safer to combine this signal with other indicators rather than acting on it alone.
On real charts, average gain and loss are usually derived from 14 periods of closing-price changes before being entered here. The result is a reference indicator based purely on past price action and does not guarantee future price direction.
Frequently Asked Questions
An RSI above 70 is generally considered overbought, and below 30 is considered oversold. These are reference levels showing trend strength, not absolute buy or sell signals.
Not necessarily. In a strong uptrend, RSI can stay above 70 for an extended period. It's common to combine RSI with other indicators, volume, and news before making a decision.
14 periods was the standard proposed by Welles Wilder, who developed RSI, and it remains the most widely used. Short-term traders sometimes use 9, while longer-term investors may use 21.