Centuries to Decades (c to dec)

1 century equals 10 decades exactly.

1 century = 10 decades

How to convert centuries to decades

To convert centuries to decades, multiply the number of centuries by 10. This factor is exact. To go the other way, multiply decades by 0.1.

decades = centuries × 10

Example: 10 centuries = 100 decades.

Months and years are not constant. This site uses the average Gregorian year of 365.2425 days, so one 'year' converts to 365.2425 days, not 365; use 'common year' for exactly 365 days.

About these units

Century (c)

CalendarCurrent unit

One hundred years.

From Latin centum, a hundred, century has meant a hundred of many things. For time it became popular as a way to speak about a span longer than a lifetime can easily contain, and some languages organise history around it: Italian uses terms like Quattrocento for the 15th century, and Swedish writes 1900-talet for the years 1900 to 1999. Whether such a century starts at year 00 or year 01 is an old argument.

A century is 100 years, which here means 100 average Gregorian years. The strict view counts from year 1, because the AD calendar has no year zero, so the 1st century AD ran from AD 1 to AD 100 and the 21st century covers 2001 to 2100. The popular view groups years by their hundreds digit, making the 20th century 1900 to 1999. The Gregorian calendar itself treats century years specially, since 1700, 1800 and 1900 were not leap years while 1600 and 2000 were.

1 century = 3,155,695,200 seconds (exactly).

Sources: Wikipedia: Century; Wikipedia: Gregorian calendar

Decade (dec)

CalendarCurrent unit

Ten years.

Greek dekas, a group of ten, gave English decade, and the Latin equivalent decennium survives in words like decennial. The idea of naming whole decades is newer. The convention of grouping years by their tens digit, so that 1960 to 1969 is the 1960s, became common in the late 19th century, and the 20th century then produced a gallery of nicknames such as the Roaring Twenties and the Swinging Sixties.

A decade is ten years, which on this site means ten average Gregorian years. The two counting styles can disagree, in the same way as with centuries: since the AD calendar has no year zero, a strict reading makes the first decade run from year 1 to year 10. A 2019 YouGov poll of 13,582 US adults found 64 percent expected the next decade to be 2020 to 2029, 17 percent said 2021 to 2030, and 19 percent did not know. Most people prefer the zero-to-nine version.

1 decade = 315,569,520 seconds (exactly).

Sources: Wikipedia: Decade; Wikipedia: Year zero

Related conversions

See all time units.