How to Use This Calculator
- 1
Enter Average Gain (Up Periods)
Input the average price gain across all 'up' periods within your chosen lookback window. This is the sum of gains divided by the number of periods.
- 2
Enter Average Loss (Down Periods)
Input the average price loss across all 'down' periods in the lookback window. Use the absolute (positive) value of the average decline.
- 3
Specify Lookback Periods
Enter the number of periods used for the RSI calculation. The standard Wilder setting is 14 periods.
- 4
Review Your Results
View the RSI value, Relative Strength (RS), Market Zone, Gain-to-Loss Ratio, and Implied Win Rate cards. The RSI Analysis insights panel shows distance to thresholds, momentum strength, and reversal risk assessment.
Example Calculation
A trader wants to calculate the RSI for a stock over 14 periods, where the average gain was $1.20 and the average loss was $0.57.
Average Gain ($)
1.2
Average Loss ($)
0.57
Lookback Periods
14
Results
RSI
67.80
Relative Strength (RS)
2.1053
Market Zone
Bullish zone (50-70)
Gain-to-Loss Ratio
2.105x
Implied Win Rate
67.8%
Tips
Watch for Divergence
RSI divergence — where price makes a new high/low but RSI doesn't — can signal a potential trend reversal. This is a powerful confirmation signal used by experienced traders.
Adjust Lookback Periods
While 14 periods is standard, shorter periods (e.g., 9) make RSI more sensitive to price changes, while longer periods (e.g., 21) smooth it out, reducing false signals. Try different values to see how RSI changes.
Combine with Other Indicators
RSI is most effective when used alongside other technical indicators such as moving averages or support/resistance levels to confirm signals and improve trading accuracy.
Use the Implied Win Rate
The Implied Win Rate shows the proportion of up periods implied by the current gain/loss ratio. At a 2.105x ratio, the implied win rate is 67.8%, meaning roughly 2 out of 3 periods are up periods.
Unlocking Market Momentum: The RSI Calculator
The RSI Calculator is an essential tool for traders and investors to gauge the momentum of an asset's price action. By inputting the average gain and loss over a specified number of periods, you can instantly compute the RSI value, Relative Strength (RS), market zone, gain-to-loss ratio, and implied win rate.
For instance, a stock with an average gain of $1.20 and average loss of $0.57 over 14 periods yields an RSI of 67.80, indicating strong upward momentum approaching the overbought threshold.
The Formula Behind RSI Calculation
The RSI is calculated in two main steps.
First, the Relative Strength (RS) is determined by dividing the average gain by the average loss.
Then RS is plugged into the RSI formula to produce an oscillator ranging from 0 to 100.
Relative Strength (RS) = average gain / average loss
RSI = 100 - (100 / (1 + RS))
Gain-to-Loss Ratio = average gain / average loss
Implied Win Rate = ratio / (1 + ratio) x 100
These formulas, developed by J.
Welles Wilder Jr. in 1978, provide a smoothed measure of price momentum over the specified lookback period.
Analyzing Stock Momentum: A Worked Example
Consider a trader analyzing a tech stock over the standard 14-period lookback.
The stock had an average gain of $1.20 during up periods and an average loss of $0.57 during down periods.
- Input Average Gain: Enter
1.2for "Average Gain (Up Periods)". - Input Average Loss: Enter
0.57for "Average Loss (Down Periods)". - Input Lookback Periods: Enter
14for "Lookback Periods".
The calculator performs these calculations:
- Relative Strength (RS):
$1.20 / $0.57 = 2.1053. - RSI:
100 - (100 / (1 + 2.1053)) = 100 - 32.20 = 67.80. - Gain-to-Loss Ratio:
$1.20 / $0.57 = 2.105x. - Implied Win Rate:
2.105 / (1 + 2.105) x 100 = 67.8%.
The RSI of 67.80 places the stock in the Bullish zone (50-70), 2.2 points from the overbought threshold of 70. The 2.105x gain-to-loss ratio confirms strong upward momentum.
Using RSI to Identify Overbought and Oversold Conditions
An RSI reading above 70 typically signals an overbought market, suggesting the asset's price has risen too quickly and may be due for a pullback. An RSI below 30 indicates oversold conditions, implying the price has fallen too sharply and might rebound. These thresholds are widely recognized in financial markets in 2026.
However, RSI signals are best used as probabilities rather than certainties. During strong trends, an asset can remain overbought or oversold for extended periods. Combining RSI with other technical analysis tools — such as moving averages, volume analysis, or support/resistance levels — provides stronger confirmation signals.
The Origins of the Relative Strength Index
The RSI was developed by J. Welles Wilder Jr., a mechanical engineer turned technical analyst, and introduced in his 1978 book "New Concepts in Technical Trading Systems." Wilder designed the RSI to more accurately identify overbought and oversold conditions than existing momentum tools. His standardization of the 14-period lookback created a robust indicator that remains one of the most popular tools in technical analysis nearly five decades later.
Frequently Asked Questions
What is the Relative Strength Index (RSI)?
The RSI is a momentum oscillator developed by J. Welles Wilder Jr. that measures the speed and change of price movements. It oscillates between 0 and 100, indicating whether an asset is overbought (above 70) or oversold (below 30). For example, with an average gain of $1.20 and average loss of $0.57, the RSI is 67.80 — approaching overbought territory.
What do overbought and oversold mean in RSI analysis?
An asset is considered overbought when its RSI rises above 70, suggesting the price has increased too rapidly and may be due for a correction. An RSI below 30 indicates oversold conditions, implying the price has declined too rapidly and may be due for a bounce. These are probabilities, not guaranteed reversals.
How does the lookback periods setting affect the RSI?
A shorter lookback (e.g., 9 periods) makes RSI more volatile and sensitive, generating more frequent signals. A longer period (e.g., 21) smooths the RSI, reducing false signals but potentially delaying entries. The standard 14-period setting balances sensitivity and reliability.
What does the RSI Analysis insights panel show?
The insights panel shows distance to overbought/oversold thresholds, momentum strength based on the RS ratio, and a reversal risk assessment based on the current RSI zone. This helps traders quickly gauge whether to hold, buy, or consider selling.
How is the Implied Win Rate calculated?
The Implied Win Rate equals the gain-to-loss ratio divided by (1 + gain-to-loss ratio), expressed as a percentage. With a gain of $1.20 and loss of $0.57, the ratio is 2.105x, giving an implied win rate of 67.8% — meaning roughly 2 out of 3 periods show gains.