WMSR (Williams %R): calculation and reading

Williams %R looks at how far the close is from the highest price of the recent period; the idea is close to KD but the direction is opposite.

Updated：2026-11-08

Calculation

WMSR = (highest high of the last N days − today’s close) ÷ (highest high of the last N days − lowest low of the last N days) × 100, with a default N = 9.

This site uses the 0-to-100 scale common in Taiwan by default: the larger the value, the closer the close is to the low of the last N days (weaker); the smaller the value, the closer it is to the high (stronger). The US-style Williams %R takes the same number with a negative sign, so it falls between −100 and 0 and the direction is exactly reversed; this site lets you switch between the two.

How to read it

• Common reference lines are 20 and 80 (on the Taiwan scale): above 80 is called the low zone, and below 20 is called the high zone. This only describes where the close sits within the range.
• It is actually the same formula as the RSV in KD seen from the other side: WMSR = 100 − RSV.

Limits

Like KD, in a strong or weak trend the value can stay at the edge of the range for a long time. It does not include volume and does not predict the future.

Where the idea comes from

Williams %R was introduced by Larry Williams. This article explains it in our own words.

This article only explains the calculation and how to read a chart. It is not investment advice.