A century
A century is a period of one hundred years.
How big is it?
100 years · time
Time · reference interval
A little perspective
A century vs Human lifetime: duration comparison
A century is about 1.25 times a human lifetime.
ELAPSED TIME
Measurements, assumptions & sources +
A century
Time: 100 years; reference interval.
One hundred Julian years for consistent conversion.
Defined examples — our methodology
The marked time is calibrated. Unmeasured illustration details are representative.
Human lifetime
Time: 80 years; reference interval.
An 80-year comparison interval, not a prediction of life expectancy.
Defined examples — our methodology
The marked time is calibrated. Unmeasured illustration details are representative.
Use the visual comparison to explore its scale, then check the measurements and sources.
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Why this measurement?
Why we use 100 years
We compare a century. The measurement is labelled reference interval. Check the source notes for its basis.
One hundred Julian years for consistent conversion.
The picture identifies the subject; the diagram compares the recorded values. How calibrated comparisons work →
Recorded properties
Dimensions and measurements
| Property | Selected value | Recorded range | Basis |
|---|---|---|---|
| 100 years | Not recorded | reference interval |
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Sources and method
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TimeBlink of an eye150 msA blink of an eye is the quick closing and opening of the eyelid, usually happening involuntarily.TimeHuman lifetime80 yearsA human lifetime is the span from a person's birth to their death.
TimeAge of Earth4.54 GyrThe age of Earth is the time that has passed since the planet formed from the solar nebula.TimeAge of the universe13.8 GyrThe age of the universe is the time since the Big Bang, marking the beginning of cosmic expansion.TimeRecorded-history interval5 kyrThe recorded-history interval is the span for which humans have kept written or documented records.
PeopleRed-cell lifespan120 daysRed-cell lifespan is the average time a human red blood cell remains in circulation before being removed from the bloodstream.
TimeVenus solar day116.8 daysA Venus solar day is the interval between two successive sunrises at the same location on Venus, which is much longer than an Earth day.TimeMoon phase synodic cycle29.53 daysThe Moon phase synodic cycle is the average time between identical lunar phases, such as from one full moon to the next.