How Long is a Decade and Why?

logo by Editorial Staff | Updated on July 3rd, 2022

The exact answer is ten years.

What is a Decade?

A decade is ten years. The word is derived (through French and Latin) from the Ancient Greek: dekas, which meant a group of ten. Decades can refer to any ten years, such as a person’s life or specific groups of calendar years.

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The decade was officially added to the English language in 1590. However, it is commonly referred to every ten years during a century. For example, the 1680s or 1930s refer to the years 1680-1689.

The significance of the decade

Anything that happens in a hundred years is considered a centennial event, while anything that happens in a thousand years is referred to as a millennial event. Therefore, the years 1990-1999 constitute the final decade of the 1990s. Whereas the years 2000 to 2009 constitute the first decade of the 2000s.

The phrase that identifies a collection or a period of a period usually begins with the number ten. However, there is no actual name for referring to 5, 20, 30, or 40-day periods. After a decade, it’s usually a century, and even 50 is only described as half a century.

Decades are used to signify different periods in the Georgian calendar. Because their calendar has no zero, if you reference the 1850s, you are referring to 1851-1860.

When establishing individual decades in a century, the Georgian calendar differs from the conventional calendar. For example, the term “eighties” commonly refers to 1980-1989. However, according to the Georgian calendar, the 190th decade runs from 1981 to 1990.

What is the length of a decade?

Using decades to represent ten years has made it easier for humans to differentiate key historical events. In addition, decades have enabled humans to rapidly recognize specific historical events, such as the 40s or 30s, which refer to the 1940s and 1930s.

Each decade is given a moniker based on noteworthy events that occurred during that period. The ‘roaring twenties,’ which refers to the period in the 1920s when there was a lot of cultural change and economic expansion, is a good example in US history.

Most historical events are separated into decades, making it easier for people to discern between events that occurred at different times in the past.

Aside from historical events, age can also be divided into decades. The following is a breakdown of ages in their respective decades:

Name of the periodNumber of Years it coversSomeone in their
Vicenarian20-29The 20s
Tricenarian30-39The 30s
Quadragenarian40-49The 40s
Quinquagenarian50-59The 50s
Sexagenarian60-69The 60s
Septuagenarian70-79The 70s
Octogenarian80-89The 80s
Nonagenarian90-99The 90s
Centenarian100 and above

The term decade has also been used to refer to the 1990s when Japan’s economy collapsed. The period was known as the “lost decade” and occurred just after World War II.

When the Finance Minister raised interest rates, the economy crashed. In addition, the price increase caused the stock market to fail, affecting the country’s economic progress.

The crisis lasted nearly a decade and continues to impact the Japanese corporate market.

What’s the Distinction Between Decades and Centuries?

A decade perplexes definition, and definition perplexes response. Some argue that at least one must be ten years long, while others argue it must be at least eleven years long. The best description we’ve discovered is that a decade is ten years long, and anything longer than ten years is called a century. However, when we apply that to larger periods, we obtain a very different definition: a millennium is 1,000 years, and anything less than that must be considered a century.

How Many Decades Are in a Century?

A century is made up of ten decades.


We know that there are ten years in a decade.

We also know that there are 100 years in a century.

As a result, if we try to find the number of decades in a century (100 years), we get:

1 decade = 10 years

? decade = 100 years

As a result of further simplification, we get:

One century is equal to ten decades multiplied by 100 years.

As a result, a century has ten decades.

A decade is calculated using the following formula:

The calculation of the decade formula is based on two degrees of view or two perspectives, one of which indicates that a new decade begins with a year (the year should have zero as the last digit) and ends with a year that also has zero as the last digit.

For example, the 1980s in the twentieth century began in 1980 and concluded in 1989.

The same is true for the twenty-first century; consider the 2000s, a decade that began in 2000 and ended in 2009.

Another point of view is that a decade begins with the last number being one and ends with the last number being zero. So, for example, the tenth decade of the twentieth century ran from 1991 to 1999. Similarly, 2030 will be the final year of this decade.

It is worth noting that 2020 is either the start of a new decade or the end of a decade; this has no bearing on life and its essence. However, this is also dependent on each individual’s point of view.

Calendar phrases that aren’t in the dictionary

A century is one hundred years, such as the nineteenth century. The nineteenth-century spans the years 1901 to 2000. A bicentennial is 200 years.

  • The term “millennium” refers to 1000 years.
  • Megaannum is a term used to describe a million years.
  • A fortnight is two weeks.
  • A score is valid for 20 years, while a lustrum is valid for five years.
  • A biennium, triennium, or quadrennium is a short period of two, three, or four years.

Why are Decades ten years?

The term decade comes from the Greek word ‘dekas,’ a group of ten. The term decade was coined by the Romans, who used the word dec- to distinguish items grouped in tens: decathlon and decagon. The two names refer to a group of ten items. As a result, the word dec- was inserted into the calendar to represent the passage of ten years.

How long is a decade in days?

Because a decade is ten years, converting it to days yields 3650 days, or 365 (1 year) x 10.

In minutes, how long is a decade?

Assuming 365 days per year, there are 5,256,000 minutes in ten years.

However, you should consider the decade in question. If you look at the years 2000-2009, you’ll notice that 2000, 2004, and 2008 are leap years. That’s an extra three days. As a result, the total number of minutes would be 5,260,320.

There would be two leap days if the year ranged from 2001 to 2010—5,258,880 minutes.

However, every 400 years, there is no leap day on years ending in 00 that begin with a non-multiple of 4, such as 1800, 1400, 1000, and 600.

How to Correctly Write the Decade

In professional writing, you should generally use decennium instead of the decade because it seems more educated and authoritative. However, it doesn’t matter which word you use in informal writing because both have the same meanings and definitions.

It would be helpful if you were also cautious when referring to decades or how long a decade is in the discussion. If we believe we are making a valid point but are not, we must check to ensure that what we are saying is correct.

Using Google’s Ngram Viewer to check for mistakes is a nice idea. For example, we could say, “I went to college in the 1990s.” However, that could imply that we graduated in 1999 or went to college in 1991 and 1992. The Ngram Viewer displays the frequency with which an expression has been used through time. It will also demonstrate how frequently two expressions are used together.

It’s critical to comprehend decade names like “the 1990s,” “the ’90s,” and “the 2000s.” They can be used as nouns or verbs (like 1990: The 1990s: The 1990s). It’s beneficial to know them, but most occupations don’t require them. Therefore, if you want to cite a decade, you must include the decade and its title.

How Do You Discuss Time Periods?

There are other ways to discuss periods. For example, people sometimes use the term decade to indicate relative time lengths. For example, if someone says, “This war has lasted for two decades,” it suggests that the war has lasted longer than it should and is more than ten years old.

It would be best if you considered the length of a decade in terms of actual years. Suppose you’re referring to something that occurred over a decade, such as the 1900s or the 1960s. You need to specify one year if you’re talking about an era or period within a decade, such as the 1990s. For instance, we could say, “My husband was born in 1975.” He was born in the 1990s.

“I was born in 1980, so I’m towards the end of the 1980s,” for example, when discussing a period spanning two decades, including both of them. “I was born in 1977″ is another example. As a result, I am a member of Generation X.” Regardless of how many decades are spanned, just one decade should be seen at the end. It should only appear once at the end if you’re referring to several decades.

How Do You Discuss More Than One Decade?

Ordinal numbers are commonly used when referring to periods or eras separated by more than a decade. For example, someone may speak of the “first decade of the new millennium.”

According to studies, teenagers and young people can be perplexed for decades. A teen, for example, may incorrectly believe that the 1960s ended more than 40 years ago. Most people your age understand what you mean when you say “the 90s.” However, if you’re talking about something that happened before 1990 or after 1999, you must identify the 1990s.

How Do You Discuss Decades Separated Time Periods?

When discussing periods separated by decades, use ordinal numbers. “The ’70s, ’80s, and ’90s were a very important era in American history,” for example. “The 1970s, 1980s, and 1990s were incredibly important decades in American history,” you can also say. It’s critical to understand what comes first if you wish to use the decades appropriately.

You can also check up on the year in the Random House Dictionary. For instance, we could say, “We recently graduated in 1999.” In the 1990s, I graduated from college.” According to the Random House dictionary, the ’90s refers to the decade of the 1990s, whereas the ’00s refers to the decade of 2000 and later.


Editorial Staff

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