Bear Years to Human Years (Calculator, Age, Chart)

Bear Years to Human Years

Use bear age calculator to convert bear years to human years. Most bear species average lifespan is 15-30 years in the wild based on habitat and gender compared to human lifespan which is 70 to 80 years.

Each bear species have slightly different lifespan.

For example

Grizzly bears, for example, can live up to 20-30 years in the wild, while polar bears can live into their 30s. In captivity, bears may live longer.

Wild black bears typically live about 18-30 years on average with exceptional bears living into their 40s. Captive black bears can live over 35 years in some cases.

Giant pandas have a lifespan of about 20 years in the wild. In captivity, they can live longer, with some individuals reaching their mid-30s or even older.

We can say that 1 bear year is equal to 5.5 human years, and a 5 year old bear is 23 years old in human years. Similarly, 100 bear years will be equal to 428 human years.

But to convert the bear age in human years more accurately, you need to understand the bear life stages and life cycle.

To make this happened, I’ve created a bear age calculator, which will help you to compare its age in human years.

Bear Years to Human Years Calculator

  1. For the first year of a bear’s life, I used an average value between 5 and 7, which is 5.5. This means a 1-year-old bear is equivalent to a 5.5-year-old human.
  2. For subsequent years, I used the value 4.27, which suggests that after the first year, each bear year is roughly equivalent to 4.27 human years.

So, the formula used is:

  • If the bear is 1 year old or less: Human Years=Bear Years×5.5
  • If the bear is older than 1 year: Human Years=5.5+((Bear Years−1)×4.27)

For example:

  • A 1-year-old bear: 1×5.5=5.5 human years
  • A 2-year-old bear: 5.5+(1×4.27)=9.77 human years
  • A 3-year-old bear: 5.5+(2×4.27)=14.04 human years

And so on.

Black bears have the longest lifespans of any bear species, while polar bears typically have the shortest lives on average. Most species average 15-30 years in the wild based on habitat and gender.

Remember that, bear years are not equivalent to human years. Bears age faster than humans in their youth and slower in adulthood. There is no perfectly standardized ratio for bear to human years.

Also Know : – Gorilla Years to Human Years

Average Lifespan of a Bear in Human Years

The average lifespan of a bear converted into human years varies by species, but here is a general breakdown:

Black Bears:

  • Wild – 25-30 human years (18-30 bear years)
  • Captive – 45-55 human years (35+ bear years)

Brown Bears/Grizzlies:

  • Wild – 26-39 human years (average 20-30 bear years)
  • Captive – Up to 58 human years (45 bear years)

Polar Bears:

  • Wild – 20-26 human years (15-18 bear years)
  • Captive – 26-39 human years (average 20-30 bear years)

Giant Pandas:

  • Wild – 20-26 human years (15-20 bear years)
  • Captive – 26-49 human years (average 20-30 bear years)

Bears can live into their 30s and beyond in terms of bear years, that translates to only 25-60 human years depending on factors like species, environment, and captivity vs wild. Generally most bears average a lifespan that would equate to around 25-40 human years.

How to Calculate a Bear’s Age in Human Years

How to Calculate a Bear Age in Human Years
How to Calculate a Bear Age in Human Years

To calculate bear age in human years identify the bear species in question (e.g., grizzly bear, black bear) and find the average lifespan for that species. For example, if you’re considering a grizzly bear, you might use the estimate of 20 to 30 years.

Here is a simple way to calculate a bear’s age in equivalent human years:

  1. For a baby bear under 2 years old: Multiply the bear’s age by 3-5 to get human years Ex. 1 bear year x 4 = 4 human years
  2. For an adult bear over 2 years old: Multiply the bear’s age by 8 to get human years Ex. 5 bear years x 8 = 40 human years

The ratio changes from 3-5 human years in baby cub stage to about 8 human years per 1 bear year in adulthood. This rough approximation accounts for bears maturing faster early on but then aging slower later in lifespan relative to a human time frame.

Some key ages comparisons:

  • 5 bear years = approximately 40 human years
  • 10 bear years = approximately 80 human years
  • 20 bear years = approximately 160 human years

A bear in its late 20s in bear years has lived the equivalent of over 200 human years once you factor in their faster maturation as cubs.

Also Know : – Deer Years to Human Years

Bear Age Chart

This chart provides a more precise breakdown of how to translate bear years to equivalent human years chart at different life stages for a bear.

Bear Years to Human Years Chart
Bear Years to Human Years Chart
  • Cubs (0-2 bear years): Ages start at 0.5 years rather than 0. This accounts for bears being born and developing rapidly in their first year. The ratio is approximately 1 bear year equals 4-5 human years for cubs.
  • Subadults (2-5 bear years): After 2 years old, bears transition from “cub” to “subadult” stage. The aging ratio declines slightly to about 1 bear year equals 4 human years.
  • Adults (5+ years): At 5 bear years, they reach mature “adulthood”, and the ratio changes to about 1 bear year equaling 8 human years. This slower 8:1 aging ratio applies for the rest of their adult life span.
  • The chart shows the very gradual, smooth progression. So for example, at exactly 3 bear years old, the equivalent human age is 15.27 years. Whereas at exactly 4 bear years, it is 19.54 human years.

This chart captures the different rates of development in cub, subadult and adult bear life phases, mapping a precise human age equivalent at each 0.5 year interval of bear age. It aims to model the bear aging process more accurately.

Know More : – Donkey Years to Human Years

Bear Life Stages

Bears go through a few key life stages:


Birth to 9 months old. Born in winter den, rely on mother’s milk.

Explore outdoors with mom at 3-4 months old in spring. Weaned by fall, about 8 months of age.


9 months to 2 years old. Still closely tied to mother, start trying some solid foods.

Will den with mother for winter sleep their second year.


2-4 years old. More independent, establish their own territory/range of males.

Disperse from mother’s range, though may temporarily reunite.


5+ years old and sexually mature.

Males compete for breeding access to females.

Females breed every 2-3 years when food is abundant.

Senior Bears:

Varies by species, >15 years considered aged. Limited breeding.

Seen as 20+ years in black bears, 18+ years in brown bears.

Gradual onset, but decreased stamina and health issues emerge.

Bears develop rapidly as cubs but reach breeding maturity around 5 years old. They transition through the teenage sub-adult phase before becoming full adults. Lifespan slows after sexual maturation.

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