RSI calculator (Wilder, 14-period)
The Relative Strength Index (RSI) is a momentum oscillator on a 0–100 scale developed by J. Welles Wilder in 1978. The standard 14-period RSI compares average gains to average losses over the last 14 closes; readings above 70 are conventionally treated as overbought and below 30 as oversold. This tool implements Wilder's smoothing exactly — not a simple average — so the value matches what you see in TradingView, Bloomberg and Drogo.
How to use
- Paste closing prices
Enter at least 15 daily closes (most recent at the bottom).
- Choose period
The standard period is 14. Use 9 for shorter-term, 21 for longer-term.
- Read the result
Drogo applies Wilder smoothing and returns the RSI for the most recent close.
Frequently asked questions
- What is a "good" RSI value?
- There is no universally good value — the indicator is contextual. Above 70 is conventionally overbought and below 30 oversold, but strong trends can sustain extreme readings for weeks. Pair with price action and a separate trend filter.
- Why does my RSI differ from another platform?
- Most discrepancies come from using a simple moving average instead of Wilder smoothing, or from different starting points. Drogo uses Wilder's recursive smoothing on the entire input series.
- Can I use intraday closes?
- Yes — the formula is timeframe-agnostic. Just feed in the closing prices of whichever bar size you trade.
Ask Drogo about this: