How this instrument works
The Duke Activity Status Index asks about twelve ordinary activities — self-care tasks like eating, dressing, and bathing, walking indoors, walking a block or two, climbing a flight of stairs, running, three grades of housework, yard work, sexual relations, moderate recreation, and strenuous sport — and gives each one a fixed weight reflecting roughly how much energy it demands. Every activity a person can manage contributes its weight to a running total, the DASI score, which ranges from 0 up to a maximum of 58.2. Mark Hlatky and colleagues at Duke University developed the index in a 1989 study, testing it against actual peak oxygen uptake measured on a treadmill in 50 patients and finding the two correlated well.
The point of DASI is estimating cardiorespiratory fitness, or functional capacity, from a short questionnaire instead of an exercise test. This calculator carries the conversion one step further, turning the DASI score into an estimated METs figure using (DASI × 0.43 + 9.6) ÷ 3.5, a formula derived from the same 1989 study's regression against measured oxygen uptake. It is a quick, low-cost stand-in for a formal test, useful for a rough read on functional capacity before deciding whether more involved testing is warranted.
DASI has found renewed use in preoperative planning: the 2024 ACC/AHA guideline on perioperative cardiovascular management for noncardiac surgery treats a DASI score below 34 as a marker of reduced functional capacity and higher perioperative risk, favoring it over a clinician's informal estimate of a patient's exercise tolerance in METs alone.
The trade-off is the one built into any self-reported measure: it asks what a person believes they can do, not what a treadmill or cardiopulmonary exercise test actually records. The original validation reported a correlation of about 0.80 with measured peak oxygen uptake — strong, but not identical — so DASI works best as a screening estimate, with formal exercise testing reserved for situations where a more precise number changes what happens next.
- Mark each of the twelve everyday activities Yes or No, from Self-care (eat, dress, bathe) through Strenuous sports (swimming, tennis, skiing).
- Each Yes adds its own weight automatically — for example Climb a flight of stairs or walk up a hill contributes 5.5, Run a short distance contributes 8.
- Read DASI score (0-58.2) — the sum of every activity marked Yes.
- Read Estimated METs — the DASI score converted via (DASI × 0.43 + 9.6) ÷ 3.5.
Worked example — a DASI score of 18.95
Someone can manage self-care, walking indoors, walking a block or two, climbing a flight of stairs, light housework, and moderate housework, but not the other six activities. Their weights add to 2.75 + 1.75 + 2.75 + 5.5 + 2.7 + 3.5 = 18.95, the DASI score. Converting to METs: 18.95 × 0.43 = 8.1485, plus the constant 9.6 gives 17.7485, and dividing by 3.5 gives about 5.07 estimated METs — a moderate functional capacity, well above the formula's floor.
The scale's two extremes bound that case. Managing none of the twelve activities gives a DASI score of 0, and even at zero the conversion doesn't reach zero METs — the formula's constant term alone works out to 9.6 ÷ 3.5, about 2.74 METs. Managing every one of the twelve activities, including running, heavy housework, yard work, sexual relations, moderate recreation, and strenuous sports, sums every weight to the maximum DASI score of 58.2, converting to about 9.89 estimated METs, a high reading for functional capacity.
Questions
What does a DASI score of 18.95 mean?
It describes someone managing basic self-care and mobility along with light and moderate housework, but not running, heavy housework, yard work, sports, or the other higher-demand activities on the list. Converted through the formula, it works out to roughly 5.07 estimated METs, a middling functional capacity rather than a low or high extreme.
How does DASI convert into an estimated METs value?
Through the formula METs = (DASI × 0.43 + 9.6) ÷ 3.5, derived from the original 1989 study's regression of questionnaire scores against measured peak oxygen uptake in Duke patients. Multiply the DASI score by 0.43, add 9.6, then divide by 3.5 to reach the estimated METs figure this calculator reports.
Is DASI a substitute for a formal exercise stress test?
No. DASI estimates functional capacity from a self-reported questionnaire, while a cardiopulmonary exercise test or treadmill study measures oxygen uptake directly under supervision. DASI correlated well with measured values in its original 1989 validation — about 0.80 — but that is a strong association, not identical agreement, so it works best as a screening step before deciding whether direct testing is needed.
Why is the DASI score used before surgery?
The 2024 ACC/AHA guideline on perioperative cardiovascular management recommends DASI as a more reliable measure of functional capacity than a clinician's informal estimate of a patient's exercise tolerance, treating a score below 34 as a signal of reduced capacity and higher perioperative risk. It gives surgical teams a quick, standardized read on fitness without needing a treadmill test for every patient.
Why doesn't a DASI score of zero convert to zero METs?
Because the conversion formula has a constant term, 9.6, added before dividing by 3.5. Even at the lowest possible DASI score of 0, that constant alone contributes 9.6 ÷ 3.5, about 2.74 METs — a reflection of the fact that the regression line behind the formula doesn't pass through the origin, not a claim that resting energy demand is ever truly zero.
Who developed the Duke Activity Status Index?
Mark Hlatky and colleagues at Duke University Medical Center, publishing their 1989 validation in the American Journal of Cardiology. They tested the twelve-item questionnaire against measured peak oxygen uptake in patients undergoing exercise testing and found the two correlated well, giving the index its ongoing use as a quick functional-capacity estimate.
References
Read this first: This instrument computes a screening figure from population formulas — it is not a diagnosis, and it cannot see the whole picture a clinician can. Use it to inform a conversation, not to replace one.