Williams %R shows where the latest close sits between the highest high and lowest low of the lookback, from 0 at the top to −100 at the bottom. Extreme readings describe position in the range, and strong trends can hold them there for a long time.
What Williams %R measures
Williams %R, also called Williams percent R, is a momentum oscillator that locates the latest close within the range of a recent window. Larry Williams made it public in his 1973 book How I Made One Million Dollars Last Year Trading Commodities, using a ten-day range. A reading of 0 means the close is at the highest high of the window, and −100 means it is at the lowest low.
- Inputs: the high, low and close of each session.
- Lookback: 14 sessions is the usual default today; Williams’ original description used ten days.
- Units: percent of the range, shown from 0 to −100.
- Cadence: each period is one session on a daily chart.
Williams’ original scale ran from 0 at the overbought end to 100 at the oversold end. Most charts now multiply by −100 instead, so the line rises when the close moves up within the range.
How to calculate Williams %R
Find the highest high and the lowest low of the lookback, including the current session. Subtract the close from the highest high, divide by the full range and multiply by −100. The tables follow 20 hypothetical sessions with a 14-session lookback.
%R = (Highest high − Close) / (Highest high − Lowest low) × −100
Fast stochastic %K = (Close − Lowest low) / (Highest high − Lowest low) × 100 = %R + 100| Session | High ($) | Low ($) | Close ($) |
|---|---|---|---|
| 1 | 58.40 | 57.20 | 57.50 |
| 2 | 57.90 | 56.60 | 56.90 |
| 3 | 57.30 | 56.10 | 56.40 |
| 4 | 56.80 | 55.60 | 56.50 |
| 5 | 56.70 | 55.30 | 55.50 |
| 6 | 55.90 | 54.60 | 54.90 |
| 7 | 55.40 | 54.20 | 55.10 |
| 8 | 55.30 | 53.80 | 54.00 |
| 9 | 54.50 | 53.10 | 53.40 |
| 10 | 54.00 | 52.70 | 53.60 |
| 11 | 53.90 | 52.40 | 52.60 |
| 12 | 53.00 | 51.80 | 52.10 |
| 13 | 52.60 | 51.30 | 51.60 |
| 14 | 52.10 | 50.90 | 51.20 |
| 15 | 52.40 | 51.00 | 52.20 |
| 16 | 53.30 | 52.00 | 53.10 |
| 17 | 54.20 | 52.90 | 54.00 |
| 18 | 54.90 | 53.60 | 54.70 |
| 19 | 55.60 | 54.30 | 55.40 |
| 20 | 56.10 | 54.90 | 55.90 |
| Session | 14-session high ($) | 14-session low ($) | Close ($) | %R | Fast %K |
|---|---|---|---|---|---|
| 14 | 58.40 | 50.90 | 51.20 | −96.0 | 4.0 |
| 15 | 57.90 | 50.90 | 52.20 | −81.4 | 18.6 |
| 16 | 57.30 | 50.90 | 53.10 | −65.6 | 34.4 |
| 17 | 56.80 | 50.90 | 54.00 | −47.5 | 52.5 |
| 18 | 56.70 | 50.90 | 54.70 | −34.5 | 65.5 |
| 19 | 55.90 | 50.90 | 55.40 | −10.0 | 90.0 |
| 20 | 56.10 | 50.90 | 55.90 | −3.8 | 96.2 |
If the highest high equals the lowest low, the stock traded at one price for the whole window and the formula divides by zero, so %R has no defined value in that case.
Overbought and oversold levels
Readings from 0 to −20 are usually called overbought: the close sits in the top fifth of the range. Readings from −80 to −100 are called oversold: the close sits in the bottom fifth. The labels describe position in the range, not value, and they say nothing about whether a move is finished.
In a strong advance, closes keep landing near the top of a rising range, so %R can stay above −20 for weeks; in a steady decline it can stay below −80. Some readers add −50 as a midline to separate the upper and lower halves of the range.
How to read Williams %R on a stock chart
Williams %R is drawn in a pane under the price chart with lines at −20 and −80. Because it is not smoothed, it moves quickly and can jump from one zone to the other within a few sessions. Read the zone, how long the line has stayed there and the session when it leaves.
- Check the lookback in the indicator label.
- Note the zone and how long the line has been in it; a long stay describes a trend.
- Mark exits from a zone, such as a move back above −80, and compare them with the price chart.
- Watch the window edges: when an old extreme leaves the window, the range shrinks and %R can move without any change in the close.
A reversal example
In the worked example, the decline ends at session 14 with a close of $51.20, near the bottom of a range from $50.90 to $58.40, and %R reads −96.0. Over the next three sessions the closes climb and %R rises to −81.4, −65.6 and −47.5, and by session 20 it reaches −3.8. Part of that rise comes from the window: as the early highs drop out, the 14-session high falls from $58.40 to $55.90 at session 19, so each close sits higher within a narrower range.
The hypothetical chart on this page shows the same pattern on a longer scale: %R stays mostly below −80 through the decline, moves back above −80 two sessions after the lowest low and then spends most of the advance above −20.
Williams %R compared with the stochastic oscillator
Williams %R and the fast stochastic %K use the same three inputs and the same range; %R is simply %K minus 100. The stochastic oscillator is usually smoothed, with a %D line or a slow version that averages %K, while %R is normally plotted raw. The result is the same information on a shifted scale, with %R reacting faster than a smoothed stochastic.
| Feature | Williams %R | Stochastic oscillator |
|---|---|---|
| Formula core | Close measured from the highest high | Close measured from the lowest low |
| Scale | 0 to −100 | 0 to 100 |
| Usual smoothing | None | A %D signal line; the slow version also smooths %K |
| Common reference lines | −20 and −80 | 80 and 20 |
In the worked example, each fast %K value is the %R value plus 100: −96.0 becomes 4.0 and −3.8 becomes 96.2. Read more in the guide to the stochastic oscillator.
Limitations of Williams %R
Its speed and simplicity make Williams %R easy to read and easy to over-read. These limits apply at every setting.
- Trend persistence. Overbought and oversold readings can last as long as the trend does.
- Noise. Without smoothing, single sessions swing the line between zones.
- Window edges. One extreme high or low controls the range until it leaves the window.
- Spikes. A brief spike sets the range for 14 sessions, even if prices traded there only for minutes.
- Flat windows. A window with no range defines no reading.
Related measures in TradeClever
TradeClever does not plot Williams %R. Its Stock Charts offer an RSI pane, another bounded momentum oscillator, and daily candles that show the highs and lows behind any range. In CleverScan, hi20FromHighPct and hi20FromLowPct give the close’s percent distance from the 20-session high and low, the same two reference points a 20-session %R uses, expressed differently.
Continue with
Sources
- Larry Williams, How I Made One Million Dollars Last Year Trading Commodities (1973), where %R was first published
- Larry Williams, Williams %R: the original ten-day range and its 0 to 100 scale (checked October 1, 2026)
Read our data and methodology notes for calculation context. This guide explains research tools and observations. It does not recommend a trade or investment.