# Months to Years and Years to Months Conversion

Both years and months are units of time, and understanding the relationship between these units is fundamental for countless applications ranging from scientific research to everyday activities.

This article helps convert months to years and years to months, providing readers with conversion calculators, tables, and simple explanations on how to use them.

Published: February 27, 2024.

## Months to Years and Years to Months Calculators

To convert time expressed in months to time expressed in years (and vice versa), feel free to use the following calculators:

Months:

Years:

Years:

Months:

## How To Convert Months to Years and Years to Months

The relationship between months and years is as follows:

T(Months) = 12 * T(Years)

T(Years) = T(Months) / 12

For short, one year has 12 months.

Few examples:

## Months to Years Examples

18 months in years → 18 / 12 = 1.5 years

21 months in years → 21 / 12 = 1.75 years = 1 year 9 months

24 months in years → 24 / 12 = 2 years

30 months in years → 30 / 12 = 2.5 years

36 months in years → 36 / 12 = 3 years

48 months in years → 48 / 12 = 4 years

60 months in years → 60 / 12 = 5 years

72 months in years → 72 / 12 = 6 years

84 months in years → 84 / 12 = 7 years

120 months in years → 120 / 12 = 10 years

180 months in years → 180 / 12 = 15 years

## Years to Months Examples

2 years in months → 2 * 12 = 24 months

3 years in months → 3 * 12 = 36 months

4 years in months → 4 * 12 = 48 months

5 years in months → 5 * 12 = 60 months

6 years in months → 6 * 12 = 72 months

7 years in months → 7 * 12 = 84 months

10 years in months → 10 * 12 = 120 months

15 years in months → 15 * 12 = 180 months

18 years in months → 18 * 12 = 216 months

20 years in months → 20 * 12 = 240 months

30 years in months → 30 * 12 = 360 months

## Months to Years and Years to Months Conversion Tables

The following tables contain the most common values given in months and years, converted into years and months.

 Months Years 1 0.0833 6 0.5 12 1 24 2 30 2.5 36 3 48 4 60 5 72 6 84 7 96 8 108 9 120 10 150 12.5 200 16.666 300 25 400 33.333 500 41.666 1000 83.333 10000 833.33

 Years Months 0.5 6 1 12 2 24 3 36 4 48 5 60 6 72 7 84 8 96 9 108 10 120 11 132 12 144 15 180 20 240 25 300 30 360 40 480 50 600 100 1200

If You wish to convert values that are not in the table, please use the conversion calculators.

## Brief History of Years and Months: Understanding the Evolution of Calendrical Systems

The measurement of time using years and months has been a cornerstone of human civilization, enabling societies to organize agricultural activities, religious festivals, and administrative duties.

The evolution of calendars reflects not only the technical advancements in astronomy and mathematics but also the cultural and political priorities of different societies throughout history.

### The Lunar Calendars: An Ancient Approach

The earliest calendars were based on the lunar cycle, with a month being roughly the time it takes for the Moon to go through all its phases (29.5 days). This system was intuitive and observable, making it ideal for early agricultural societies.

The Sumerians and the Egyptians were among the first to develop lunar calendars, around 3000 BCE. These calendars, however, needed regular adjustments to stay in sync with the agricultural seasons, since 12 lunar months fall short of a solar year by about 11 days.

### The Solar Calendars: Aligning with the Sun

The limitations of lunar calendars led to the development of solar calendars, which were based on the Earth's revolutions around the Sun. The Egyptian Calendar, one of the earliest solar calendars, was introduced around 2700 BCE.

It consisted of 12 months of 30 days each, with an additional 5 days added at the end of the year to align with the 365-day solar cycle. However, this calendar did not account for the extra quarter day in the solar year, which led to the introduction of leap years in the Julian Calendar.

### The Julian Calendar: A Roman Innovation

Julius Caesar, in 46 BCE, reformed the Roman calendar to create the Julian Calendar. It introduced a leap year every four years to incorporate the additional quarter day of the solar year.

The Julian year was set at 365.25 days, divided into 12 months with varying lengths. Despite its advances, the Julian Calendar still accumulated an error of about one day every 128 years, leading to significant misalignment over centuries.

### The Gregorian Calendar: A Modern Standard

To correct the inaccuracies of the Julian Calendar, Pope Gregory XIII introduced the Gregorian Calendar in 1582. This calendar refined the leap year rule by excluding three leap years every 400 years, effectively setting the year at an average length of 365.2425 days, which closely approximates the solar year.

The Gregorian Calendar is the most widely used calendar system today, serving as the international standard for civil use.

### Months and Their Names

The names of the months have evolved from their Roman origins, with many reflecting the gods, festivals, or numerical position in the calendar. For example, January is named after Janus, the Roman god of doors and gates, symbolizing beginnings.

Similarly, March was named after Mars, the god of war, and was originally the first month of the year in the Roman calendar. Other months, like September, October, November, and December, retain their names from their positions in the original Roman calendar (seventh, eighth, ninth, and tenth months, respectively).

### Few Final Words

The history of measuring time through years and months is a fascinating journey through human ingenuity and adaptation. From ancient lunar calendars to the modern Gregorian system, societies have continuously refined their methods to more accurately reflect the cycles of the moon, the sun, and the seasons.

These calendars have not only served practical purposes but also shaped the cultural and religious practices of civilizations across millennia. Today, the Gregorian Calendar stands as a testament to this enduring quest to harmonize human life with the rhythms of the cosmos.