The Subjective Units of Distress Scale comes from Joseph Wolpe, the behavior therapist who introduced it with Arnold Lazarus in a 1966 book and who called a single point on it a sud. A 2025 review of the scale traces that history and tests how well it has held up. This page is an independent tool that Fabulous built around Wolpe's idea; none of its wording comes from his books, and no one connected with him has reviewed or endorsed it.

What the number is for

Distress is hard to describe from the inside. "I feel awful" covers a lot of ground, and so does "a bit on edge". A number turns that ground into a ruler. Wolpe asked people to think of the worst anxiety they had ever felt or could imagine and call it a hundred, then to picture complete calm and call that zero.

Therapists still use it to rate the start and end of a session and to rank the steps of an exposure plan. On your own, it does something simpler: it tells you how big a feeling is before you decide what to do about it. A bare number drifts, though. Your sixty this week may have been a forty last month.

Anchors in your own words

The review argues that a rating is hard to read unless you know what the person was rating. It points to a practice from Prolonged Exposure therapy for PTSD, where therapists help clients write personal examples for zero, twenty-five, fifty, seventy-five and a hundred and keep them fixed for the whole course of treatment. The authors suggest this may make ratings clearer and more consistent, and they are candid that it has not been properly tested yet.

This dial borrows that structure. Each mark starts with printed words that you replace with your own: a body feeling, a place, a particular afternoon. Once a mark is yours, its number on the dial turns to handwriting. For the hundred, a code word for your worst memory is plenty.

How the dial works

Slide the needle or tap the face, and the page names the mark your reading sits closest to. That comparison is the whole trick: is this more like my fifty or my seventy-five?

Before you try something that usually settles you, park the brass hand at your number and name the skill. Afterwards, move the needle to where you are now and log the round; the shaded arc between the hands is what that attempt took off. The ledger lays every skill on one line from zero to a hundred, with a brass ring where you tend to start and an ink dot where you tend to end. It names the skill that has brought your number down most, and says so plainly when that lead rests on a single try.

What the evidence says, and what it does not

The scale has some support. In a study of sixty-one people treated with EMDR at a trauma clinic, first-session ratings rose and fell with questionnaire scores for depression, anxiety and trauma-related distress, and the rating at the end of that session tracked how much clinicians judged each person had improved by the end of treatment.

The 2025 review is blunter about the limits. It concludes that the scale has significant weaknesses as a precise measure, partly because distress has never been tightly defined and partly because it is often left unclear whether a rating describes the moment or the peak. So rate the moment, not the worst point of the day, with your marks in view.

One limit no page can fix: distress often eases with time whether or not you do anything, so a drop after a skill mixes the skill with the minutes that passed. Read the ledger as a pattern across many rounds, never as proof.

Coping skills are not exposure

Keep this ledger for coping skills, not for exposure practice. In exposure work, where you face something you fear on purpose, a falling number is not the aim. Michelle Craske and colleagues review evidence that neither how far fear drops during an exposure nor where it ends predicts how people fare in the long run. They also describe safety signals, such as a phone or another person nearby, which ease fear in the moment and let it return once they are gone. A calming skill used halfway through an exposure can do the same job. Working up a fear ladder is exposure therapy, best done with a trained clinician; if you have one, ask before you bring a skill into an exposure.

When to use it

Write your marks on an ordinary afternoon, when zero is easy to remember, then take readings at small moments as well as big ones: a sharp email, a crowded train, the minute before a dreaded call. Short skills give the needle a fair test, so 5-4-3-2-1 Grounding and The Physiological Sigh make good first entries. For a child, The Feelings Thermometer swaps numbers for five pictured levels.

A reading tells you how big a feeling is, not what it means. If your needle sits high most days, or distress is crowding out work, sleep or the people around you, take a few weeks of readings to a doctor or a licensed therapist.