Century (c) - Unit Information & Conversion
What is a Century?
Definition
A century is a unit of time equal to 100 consecutive years. It is widely used for marking long periods, especially in historical contexts and for discussing long-term trends.
History
The word "century" derives from the Latin "centum," meaning one hundred. In ancient Rome, a centuria was initially a military unit of about 100 soldiers. The application of the term to a period of 100 years became common with the development and standardization of calendar systems, particularly the Julian and Gregorian calendars, used for historical dating.
Common Uses
Centuries are primarily used for:
- Dating historical eras: (e.g., the 18th century refers to the years 1701-1800).
- Discussing long-term trends: Examining historical, cultural, social, or geological changes spanning multiple generations.
- Marking centennials: Celebrating significant 100th anniversaries.
- Grouping years: Organizing timelines in genealogy and long-term planning.
Unit FAQs
How many years are in a century?
A century is defined as exactly 100 years.
When did the 21st century begin?
Following the standard definition where centuries start with year '01, the 21st century began on January 1, 2001, and will end on December 31, 2100. This is because the calendar count started with year 1 AD, not year 0.
Is a century a standard unit in science?
While commonly understood, the century is not a base or derived unit within the International System of Units (SI). The SI unit for time is the second. Scientists typically use years (often specified as Julian years for consistency) or multiples like kiloyears (kyr) or megayears (Myr) for very long timescales.
Century Conversion Formulas
To Second:
To Minute:
To Hour:
To Day:
To Week:
To Month:
To Year:
To Millisecond:
To Microsecond:
To Nanosecond:
To Decade:
To Millennium:
To Fortnight:
To Planck Time:
To Shake:
To Sidereal Day:
To Sidereal Year:
Convert Century
Need to convert Century to other time units? Use our conversion tool.