Months to years
Multiply months by 0.0833333 to get years.
18 mo = 1.5 yr
How to convert months to years
The year is a conventional average of 365.25 days (the Julian year); a common calendar year is 365 days, a leap year 366. The month is about 30.44 days on average — a twelfth of a 365.25-day year, not a calendar month (which runs 28 to 31 days).
Worked example — 18 mo: 18 × 0.0833333 = 1.5 yr.
Months to years table
| Months | Years |
|---|---|
| 1 mo | 0.0833333 yr |
| 3 mo | 0.25 yr |
| 6 mo | 0.5 yr |
| 12 mo | 1 yr |
| 18 mo | 1.5 yr |
| 24 mo | 2 yr |
| 36 mo | 3 yr |
| 60 mo | 5 yr |
| 120 mo | 10 yr |
Reverse and related
About months and years
Month (mo)
1 mo = 0.0833333 yrDefinition. About 30.44 days on average — a twelfth of a 365.25-day year, not a calendar month (which runs 28 to 31 days)
History and origin
The month began as the period of the lunar phases, about 29.5 days, but calendar months were fixed at 28 to 31 days to fit twelve into a year. For conversions an average month is taken as a twelfth of a year, about 30.44 days.
Current use
Months organise the calendar, billing cycles and subscriptions, and count durations such as pregnancies and projects.
Source: IAU/ISO 80000-3 Julian year: 1 a = 365.25 d exactly, a convention for expressing durations. The average month here is that year divided by 12. Neither is an SI unit.
Year (yr)
1 yr = 12 moDefinition. A conventional average of 365.25 days (the Julian year); a common calendar year is 365 days, a leap year 366
History and origin
The year is the time the Earth takes to orbit the Sun, about 365.24 days. The calendar keeps step with 365-day common years and 366-day leap years, which average to 365.25 days over a four-year cycle.
Current use
Years measure age, long durations, interest and anything counted across seasons.
Source: IAU/ISO 80000-3 Julian year: 1 a = 365.25 d exactly, a convention for expressing durations. The average month here is that year divided by 12. Neither is an SI unit.
Where people use this
Months: durations, billing and subscriptions. Years: age, long durations, interest. 12 months is exactly 1 year.
Every value is carried to full double precision; the display is rounded.
Both units are defined in IAU/ISO 80000-3 Julian year: 1 a = 365.25 d exactly, a convention for expressing durations. The average month here is that year divided by 12. Neither is an SI unit..
Questions people ask
How many years is 18 months?
18 months is 1.5 years.
How many years is 24 months?
24 months is 2 years, and 36 months is 3 years.
How many years is 6 months?
6 months is half a year (0.5 years).