Differences Between Human Life Span and Expectancy

The human lifespan is the maximum number of years an individual from the human species can live based on observed examples. Though this definition of lifespan may seem simple enough, it is often confused with other common concepts in the study of the aging, life, and death of living organisms.

In order to better understand the human lifespan, let's dive a little deeper into the concept and its important distinctions from other commonly used terms.

Senior couple at a backyard party
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Human Life Span vs. Human Life Expectancy

The term lifespan is most commonly confused with another important concept: life expectancy. While both terms relate to the number of living years, they actually define very different concepts. While the term lifespan refers to the maximum number of years an individual can live, life expectancy refers to an estimate or an average number of years a person can expect to live. Most simply put, life expectancy can be attributed to and impacted by an individual and their personal health history, genetics, and lifestyle, whereas lifespan holds for all living humans.

For example, a person's life expectancy is affected by personal factors like family history, environment, diet, and even age and sex. One person's life expectancy might be different from your life expectancy and it may even change over time. Your life spans, however, are one in the same. We all share it as members of the same species. So what is the human life span?

What Is the Human Life Span?

Given that the human lifespan is defined by the longest observed human life from birth to death, it is a figure that has changed over the years. For humans, the current accepted maximum lifespan is 122 years. This age was achieved by Jeane Louise Calment of France. Calment lived from February 21, 1875, to August 4, 1997, until she was exactly 122 years and 164 days old. Remarkably, Calment remained relatively healthy and mentally intact until her 122nd birthday.

Though there have certainly been claims of longer lives, none of the claims were acceptably documented and verified.

Closing the Gap Between Life Expectancy and Life Span

With the United State's average life expectancy currently hovering at around 79 years, the age to which most Americans can expect to live is still forty-four years younger than the human lifespan. So how do we close that gap and elongate our lives? There will always be factors that are out of our individual control like our inherited genes, but we shouldn't discount the impact of those that we can control. It is generally understood that closing the gap between life expectancy and lifespan can be done through healthier living, less exposure to toxins, the prevention of chronic illnesses, and a little bit of luck.

2 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Wilhelm P. Jeanne Calment: Validation of the Duration of Her Life. Validation of Exceptional Longevity. Odense University Press. ISBN 87-7838-466-4

  2. United Nations Development Programme. Human Development Report 2019 (PDF). 10 December 2019.

By Mark Stibich, PhD
Mark Stibich, PhD, FIDSA, is a behavior change expert with experience helping individuals make lasting lifestyle improvements.