Century to Millennium Conversion Calculator: Free Online Tool

Convert centuries to millennia with our free online time converter.

From:

Century

To:

Millennium

How to Use the Calculator:

Enter the value you want to convert in the 'From' field (Century).
The converted value in Millennium will appear automatically in the 'To' field.
Use the dropdown menus to select different units within the Time category.
Click the swap button (⇌) to reverse the conversion direction.

How to Convert Century to Millennium

Converting Century to Millennium involves multiplying the value by a specific conversion factor, as shown in the formula below.

Formula:

1 Century = 0.1 millennia

Example Calculation:

Convert 60 centuries: 60 × 0.1 = 6 millennia

Disclaimer: For Reference Only

These conversion results are provided for informational purposes only. While we strive for accuracy, we make no guarantees regarding the precision of these results, especially for conversions involving extremely large or small numbers which may be subject to the inherent limitations of standard computer floating-point arithmetic.

Not for professional use. Results should be verified before use in any critical application. View our Terms of Service for more information.

What is a Century and a Millennium?

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.

A millennium is a unit of time equal to 1000 consecutive years. It is used to denote very long periods, particularly in historical, geological, and cosmological contexts.

Note: The Century is part of the imperial/US customary system, primarily used in the US, UK, and Canada for everyday measurements. The Millennium belongs to the imperial/US customary system.

History of the Century and Millennium

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.

The word "millennium" comes from the Latin words "mille" (thousand) and "annus" (year). Its use became prominent with the adoption of the Anno Domini (AD) calendar system, particularly around the year 1000 AD and later around 2000 AD, sparking discussions about the start and end of millennia based on calendar counting.

Common Uses for centuries and millennia

Explore the typical applications for both Century (imperial/US) and Millennium (imperial/US) to understand their common contexts.

Common Uses for centuries

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.

Common Uses for millennia

Millennia are used for:

Historical Epochs: Dividing history into large blocks (e.g., the 1st millennium AD, the 3rd millennium BC).
Geological Time Scales: Discussing events over thousands of years in geology, paleontology, and archaeology.
Long-Term Planning: Referring to very long-term societal, environmental, or astronomical projections.
Religious/Eschatological Contexts: Many religions have concepts related to millennial periods, prophecies, or cycles.
Cultural Milestones: Marking significant thousand-year anniversaries or transitions.

Frequently Asked Questions

Questions About Century (c)

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.

About Millennium (ka)

How many years are in one millennium?

A millennium consists of exactly 1000 years.

When did the 3rd millennium begin?

Following the standard convention where centuries and millennia start with year '01 (because the calendar started at 1 AD, not 0), the 3rd millennium AD began on January 1, 2001, and will end on December 31, 3000.

Is the millennium an SI unit?

No, the millennium is not part of the International System of Units (SI). The base SI unit for time is the second. For very long timescales, scientists often use years (like Julian years for consistency) or multiples such as kiloyears (kyr, often represented as 'ka' for kiloannum), megayears (Myr), or gigayears (Gyr).

Conversion Table: Century to Millennium

Century (c)	Millennium (ka)
1	0.1
5	0.5
10	1
25	2.5
50	5
100	10
500	50
1,000	100

All Time Conversions

Second to Minute Second to Hour Second to Day Second to Week Second to Month Second to Year Second to Millisecond Second to Microsecond Second to Nanosecond Second to Decade Second to Century Second to Millennium Second to Fortnight Second to Planck Time Second to Shake Second to Sidereal Day Second to Sidereal Year Minute to Second Minute to Hour Minute to Day Minute to Week Minute to Month Minute to Year Minute to Millisecond Minute to Microsecond Minute to Nanosecond Minute to Decade Minute to Century Minute to Millennium Minute to Fortnight Minute to Planck Time Minute to Shake Minute to Sidereal Day Minute to Sidereal Year Hour to Second Hour to Minute Hour to Day Hour to Week Hour to Month Hour to Year Hour to Millisecond Hour to Microsecond Hour to Nanosecond Hour to Decade Hour to Century Hour to Millennium Hour to Fortnight Hour to Planck Time Hour to Shake Hour to Sidereal Day Hour to Sidereal Year Day to Second Day to Minute Day to Hour Day to Week Day to Month Day to Year Day to Millisecond Day to Microsecond Day to Nanosecond Day to Decade Day to Century Day to Millennium Day to Fortnight Day to Planck Time Day to Shake Day to Sidereal Day Day to Sidereal Year Week to Second Week to Minute Week to Hour Week to Day Week to Month Week to Year Week to Millisecond Week to Microsecond Week to Nanosecond Week to Decade Week to Century Week to Millennium Week to Fortnight Week to Planck Time Week to Shake Week to Sidereal Day Week to Sidereal Year Month to Second Month to Minute Month to Hour Month to Day Month to Week Month to Year Month to Millisecond Month to Microsecond Month to Nanosecond Month to Decade Month to Century Month to Millennium Month to Fortnight Month to Planck Time Month to Shake Month to Sidereal Day Month to Sidereal Year Year to Second Year to Minute Year to Hour Year to Day Year to Week Year to Month Year to Millisecond Year to Microsecond Year to Nanosecond Year to Decade Year to Century Year to Millennium Year to Fortnight Year to Planck Time Year to Shake Year to Sidereal Day Year to Sidereal Year Millisecond to Second