Frailty Index Calculator

The frailty index is a screening measure developed by Kenneth Rockwood and Arnold Mitnitski that estimates frailty by counting health deficits — symptoms, diseases, disabilities and abnormal signs — and dividing the number present by the number assessed. A score of 0 means no deficits and 1 means every assessed deficit is present; in practice scores rarely exceed about 0.67. It is a research and screening tool, not a clinical diagnosis.

Frailty Index = (deficits present) ÷ (deficits assessed). Each item scores 0 (absent), 0.5 (partial or occasional) or 1 (present). For example, 10 deficits out of 40 assessed items gives 10 ÷ 40 = 0.25. Items you skip are excluded from both the numerator and the denominator, and at least 30 assessed items are recommended for a stable score.

This calculator uses research screening bands: below 0.08 is non-frail (fit), 0.08 to below 0.25 is pre-frail, and 0.25 or above is frail. The 0.25 threshold is widely used in frailty research to define frailty. These are screening categories from research — not a clinical diagnosis — and scores predict risk at the population level, not for any individual.

Pre-frail (frailty index 0.08 to below 0.25) means deficits are accumulating but still limited — research suggests this is the window where exercise, nutrition and medication review may slow or reverse decline. Frail (0.25 and above) means enough deficits have accumulated that the body's reserves are substantially reduced, which research links to higher population rates of hospitalization and mortality. Both labels are screening categories, not diagnoses.

No. The frailty index (deficit accumulation) counts dozens of individual deficits to produce a continuous score from 0 to 1. The Clinical Frailty Scale is a separate 9-point judgement-based scale ranging from Very Fit to Terminally Ill. Both were developed by Rockwood and colleagues, and both are used in geriatric research and care, but they are different instruments.

The frailty index is increasingly used in perioperative research because higher scores are associated at the population level with more post-operative complications, longer hospital stays and higher care needs after discharge. You can complete this screening checklist and bring the result to your pre-operative appointment so your surgical team can assess you properly. It does not predict your personal surgical outcome and never replaces clinical evaluation.

No — not for you personally. The frailty index was validated as a population-level predictor: groups with higher scores have higher average rates of hospitalization, institutionalization and mortality. It cannot predict what will happen to any individual, which is why results should always be discussed with a clinician who knows your full history.

Frailty is considered a dynamic state rather than a fixed one, and research suggests it can improve — especially in the pre-frail stage — with interventions such as progressive resistance exercise, adequate protein intake, medication review and treatment of underlying conditions. Any plan should be made with your clinician, particularly if you have heart disease or other serious conditions.

Frailty index research recommends at least 30 deficits covering multiple domains (medical conditions, function, cognition, general health) for a stable, reproducible score; adding more items beyond that changes the result very little. This calculator uses 40 items across four domains, and skips items you are unsure about so only assessed items count toward your score.

Self-reported deficit checklists correlate reasonably with clinically assessed frailty indices in research, but they are less precise: people may over- or under-report symptoms, and some deficits need examination or tests to judge. Treat a self-assessed score as a screening signal and a conversation starter with your clinician, not a definitive measurement.

Use it as a prompt for a conversation with your clinician — especially before surgery or when planning care for an older adult. People in the pre-frail band often benefit most from discussing exercise, nutrition, sleep and a medication review. If your score is 0.25 or above, ask your clinician about a comprehensive geriatric assessment. This tool gives no medical advice and makes no diagnosis.

The deficit-accumulation frailty index was developed by Kenneth Rockwood and Arnold Mitnitski at Dalhousie University, first described in the early 2000s. It has since been validated in dozens of population studies across community, hospital and long-term-care settings as a predictor of adverse health outcomes.