Alzheimer's Life Expectancy Calculator

Alzheimer's disease affects memory, reasoning, communication, mobility, and eventually many basic body functions. Survival after diagnosis varies substantially, so no calculator can determine exactly how long one person will live. Age at diagnosis is one of the strongest population-level predictors: people diagnosed at younger ages often live longer after diagnosis than people first diagnosed later in life. Disease stage also matters because an early diagnosis generally occurs farther from the advanced complications that most affect survival. Overall physical health, frailty, cardiovascular disease, diabetes, recurrent infections, falls, and nutritional problems can further change an individual's outlook. This calculator creates a transparent educational estimate from three inputs. It begins with an age-based remaining-survival baseline, then applies a factor for early, moderate, or severe disease and another factor for additional health conditions. The result is displayed to one decimal place. This simplified model is intended to illustrate how prognosis factors can interact; it is not a validated clinical prediction rule. Actual published median survival estimates differ according to the population studied, when symptoms began, how diagnosis was established, sex, care setting, and whether researchers measure from symptom onset or formal diagnosis. Use the estimate as a starting point for discussion rather than a deadline. Alzheimer's progression is not linear. A person may remain stable for a period and then decline after an infection, hospitalization, medication change, fall, or loss of mobility. Supportive care can improve comfort and daily function even when it does not alter the underlying disease. Regular reviews can address hearing and vision, sleep, pain, mood, medication side effects, hydration, nutrition, home safety, caregiver strain, and advance care preferences. Care planning should reflect the person's values and current abilities. Families may want to discuss legal and financial arrangements while the person can participate, identify preferred decision makers, and ask what changes should trigger additional home support, palliative care, or hospice evaluation. A clinician who knows the full medical history can interpret changes more accurately than an online estimate. Seek prompt medical assessment for sudden confusion, fever, breathing difficulty, a new fall, inability to drink, or an abrupt decline, because these changes may represent a treatable illness rather than expected dementia progression.