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Duke Treadmill Score Calculator

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Calculate the Duke Treadmill Score from exercise time, ST-segment deviation, and angina index to estimate cardiovascular risk after an exercise stress test.

Reviewed by the thecalcu.com team · Last updated July 14, 2026

Exercise Time
min
Max ST-Segment Deviation
mm
Angina Index

Duke Treadmill Score

0

Risk Category

—

Not a substitute for clinical judgment. This score can inform referral for cardiac catheterization but must always be interpreted by a qualified cardiologist alongside the full stress test and clinical picture.

What is a Duke Treadmill Score?

The Duke Treadmill Score Calculator computes the Duke Treadmill Score (DTS), a widely used clinical tool that combines exercise time, ST-segment deviation, and angina symptoms from an exercise stress test into a single risk-stratification number. The score helps estimate the likelihood of significant coronary artery disease and future cardiac events, and is commonly used to help decide whether further invasive cardiac testing is warranted.

Enter your exercise test results below to see your Duke Treadmill Score and risk category. For a related coronary risk tool used in a different clinical context, see the CVD Risk Calculator; for acute coronary syndrome risk stratification, see the GRACE Calculator.

Why Use a Duke Treadmill Score Calculator?

Subtracting two weighted penalties from exercise time by hand is simple arithmetic, but getting the angina index or ST-segment deviation entry wrong easily produces a misleading score. This calculator performs the calculation instantly and shows exactly how each component contributed to your final result.

It's useful for reviewing your own stress test report ahead of a cardiology follow-up, or for students and clinicians double-checking a worked Duke Treadmill Score example.

Who Should Use This Calculator?

Patients who have recently completed an exercise treadmill stress test and want to understand how their cardiologist is interpreting the results can use this calculator as an educational reference. Cardiology, nursing, and exercise physiology students studying stress test risk stratification can check worked examples against the published Duke Treadmill Score formula.

This calculator is strictly for informational and educational purposes and is not a substitute for a cardiologist's clinical judgment. Decisions about further invasive testing, such as cardiac catheterization, must always be made by a qualified cardiologist who has reviewed your complete stress test tracing and clinical history, never from this tool alone.

What Insights Does the Duke Treadmill Score Calculator Give You?

Duke Treadmill Score is the primary result, a single number, which can be negative, combining your exercise time with penalties for ST-segment deviation and angina symptoms.

Risk Category translates that score into a plain-language low, moderate, or high risk classification, reflecting how the original validation studies stratified patients by likelihood of significant coronary disease and future cardiac events.

How to use this Duke Treadmill Score calculator

  1. Enter your Exercise Time in minutes, as completed on the treadmill protocol.
  2. Enter your Max ST-Segment Deviation in millimeters, from the ECG tracing during the test.
  3. Select your Angina Index, no angina, non-limiting angina, or exercise-limiting angina.
  4. Review your Duke Treadmill Score and Risk Category, and discuss the result with a qualified cardiologist.
Show formula & methodology ↓Show less ↑

Formula & Methodology

Duke Treadmill Score = Exercise time (minutes) − (5 × max ST-segment deviation in mm) − (4 × angina index)

Where the angina index is 0 (no angina), 1 (non-limiting angina), or 2 (exercise-limiting angina). Risk bands: a score of +5 or higher is low risk, −10 to +4 is moderate risk, and −11 or lower is high risk (Mark DB, et al. N Engl J Med. 1991;325(12):849-853).

Worked example: A patient who exercises for 9 minutes with 2mm of ST-segment depression and non-limiting angina scores: 9 − (5 × 2) − (4 × 1) = 9 − 10 − 4 = −5 points, placing them in the moderate-risk category where further evaluation is often considered based on the complete clinical picture.

Frequently Asked Questions

What is the Duke Treadmill Score used for?
The Duke Treadmill Score (DTS) combines exercise time, ST-segment deviation, and angina symptoms from a standard exercise stress test into a single number that stratifies patients into low, moderate, or high risk of future cardiac events. It was developed and validated to help decide whether further invasive testing, such as cardiac catheterization, is warranted.
How is the Duke Treadmill Score calculated?
The formula is DTS = exercise time in minutes minus (5 times the maximum ST-segment deviation in millimeters) minus (4 times the angina index). The angina index is 0 for no angina, 1 for non-limiting angina, and 2 for exercise-limiting angina that stops the test.
What do the risk categories mean?
A score of +5 or higher indicates low risk, a score between −10 and +4 indicates moderate risk, and a score of −11 or lower indicates high risk of future cardiac events. These bands correspond to differing likelihoods of significant coronary artery disease and adverse outcomes in the original validation studies.
Why can the Duke Treadmill Score be negative?
Because both the ST-segment deviation penalty and the angina penalty are subtracted from exercise time, a patient with significant ST depression and exercise-limiting angina but short exercise duration can end up with a negative total. A more negative score reflects a worse combination of findings and correspondingly higher estimated risk.
What exercise protocol was the Duke Treadmill Score validated on?
The score was originally derived and validated using the standard Bruce treadmill protocol, the most widely used exercise stress test protocol in North America. Exercise time entered into this calculator should reflect the total time completed on that or an equivalent protocol.
What counts as 'non-limiting' versus 'exercise-limiting' angina?
Non-limiting angina means the patient experiences chest pain during the test but is able to continue exercising to their planned endpoint. Exercise-limiting angina means the chest pain itself is the reason the test was stopped early, which carries a higher angina index and correspondingly reduces the score more.
Can this score be used for people who can't exercise on a treadmill?
The Duke Treadmill Score specifically requires an exercise treadmill test and does not apply to pharmacologic stress tests (using medications rather than exercise) or to patients unable to exercise adequately. Alternative risk-stratification approaches are used for those patients.
Does a low-risk Duke Treadmill Score rule out coronary artery disease?
A low-risk score reduces the estimated probability of significant disease and adverse outcomes but does not eliminate it entirely, especially in patients with a strong clinical suspicion or atypical presentations. It's one input among several that a cardiologist weighs when deciding on further testing.
Can this calculator tell me whether I need a cardiac catheterization?
No, this calculator is for informational and educational purposes only and simply reproduces the published Duke Treadmill Score formula. Decisions about further invasive testing must always be made by a qualified cardiologist who has reviewed your complete stress test tracing and clinical history, not from this tool alone.
Who originally developed the Duke Treadmill Score?
The score was developed by Mark DB and colleagues and published in the New England Journal of Medicine in 1991, based on a large cohort of patients undergoing exercise treadmill testing for suspected coronary artery disease. It remains one of the most widely cited and used exercise test risk scores in cardiology.
How does this relate to the CVD Risk Calculator in this same tool set?
The [CVD Risk Calculator](/cvd-risk-calculator/) estimates baseline 10-year cardiovascular risk from static factors like cholesterol and blood pressure, while the Duke Treadmill Score reflects how a patient's heart actually performs under a real exercise test. They provide complementary but distinct types of risk information.
Is heart rate response part of the Duke Treadmill Score?
No, the standard Duke Treadmill Score uses only exercise time, ST-segment deviation, and angina index. Heart rate recovery and chronotropic response are separate, related concepts sometimes assessed alongside stress testing but are not part of this specific formula.
Also known as
Duke treadmill score calculatorexercise stress test risk calculatortreadmill exercise test score calculatorcardiac stress test risk calculatorDTS calculator