A longevity calculator is a quiz, or series of questions, that is designed to predict an individual’s life span or life expectancy. Longevity calculators are usually sponsored by private organizations, universities, medical groups, and some financial services. Most calculators ask a set of questions on lifestyle, age, and health, then predict how those characteristics will affect lifespan. The result of a longevity calculator is an age—“you will live to be 89,” for instance—with a top score of 100 years of life expectancy. Most calculators also offer advice on how to improve the projected age by changing behaviors now.
There is some controversy with respect to which of the many longevity calculators was the original, and which is the most accurate. People have been using algorithms to predict life expectancy for decades. The popularity of calculating life expectancy and life span with longevity calculators surged in popularity in the mid-1990s. The range of calculators available has grown with the advent of the Internet.
The questions that the calculators pose vary widely, but generally cover five basic categories. Most ask questions on demographics, such as physical location, air quality, and quality of life; lifestyle, including smoking and drinking habits; nutrition and questions on typical diet; medical, often including blood pressure and cholesterol readings; and information on family history. Some calculators ask exhaustive questions that cover several pages, while others can be completed in a matter of minutes. There is very little consistency of results from calculator to calculator. Most calculators are clear at the outset that their predictions should be taken only as estimates or rough guidelines.
The primary goal of the longevity calculator is not usually to nail down a specific age or aging potential. Most people use the calculator’s predicted age of death as a starting place to improve that number over time. Almost all longevity calculators available online provide advice at the end of the quiz about how to improve the results, usually including links to various websites. The longevity calculator might recommend quitting smoking, for instance, or might advise a person to change his or her diet, or get more exercise. Depending on the sponsor, the advice is often connected to specific products or services that can help achieve the desired results.
No longevity calculator can flawlessly predict life expectancy or how environmental factors will influence aging or death. Answering the questions in one or more longevity calculators can be a good indication of any behaviors that are negatively affecting life expectancy, however. Most calculators are set up with the top score of 100 years of life expectancy, and while no person or program can guarantee that anyone will live to 100, getting a sense of personal standing now can be a good way to improve the chances of living to see a full century.