Convert years to months
Convert years to months instantly. 1 yr = 12 mo. Formula, worked examples and a quick reference table.
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One year equals 12 months. To convert any number of years to months, multiply by 12.
The converter above works in both directions and updates as you type. Below you will find the formula, a worked example and a reference table of common values.
Time conversions are exact down to the day and approximate above it. Seconds, minutes, hours and days have fixed ratios, but a month has no fixed length and a year has two — 365 days in the calendar and 365.25 in the astronomical convention used here. For anything with legal or contractual weight, count the actual calendar dates rather than converting a duration, because the difference accumulates precisely where it is least welcome.
years to months formula
To go the other way, use year = month ÷ 12.
About these units
This uses the Julian year of 365.25 days, the astronomical convention. A calendar year is 365 or 366 days depending on leap years.
A month has no fixed length, so conversions use the average Gregorian month of 30.44 days. For anything contractual, count calendar dates rather than converting.
Year is also written years and yrs. Month is also written months and mos.
Sources
- International Astronomical Union, Resolution B2 (2012), XXVIII General Assembly — the astronomical unit as exactly 149,597,870,700 m, and the Julian year of 365.25 days from which the light year and parsec follow.
years to months conversion table
| Year | Month |
|---|---|
| 1 yr | 12 mo |
| 2 yr | 24 mo |
| 3 yr | 36 mo |
| 5 yr | 60 mo |
| 10 yr | 120 mo |
| 20 yr | 240 mo |
| 25 yr | 300 mo |
| 50 yr | 600 mo |
| 100 yr | 1,200 mo |
| 250 yr | 3,000 mo |
| 500 yr | 6,000 mo |
| 1,000 yr | 12,000 mo |
Frequently asked questions
How many months are in a year? +
There are 12 months in one year.
What is 10 yr in mo? +
10 yr equals 120 mo. Multiply 10 by 12.
How do I convert month back to year? +
Use year = month ÷ 12. The converter above handles both directions, or see our dedicated months to years page.
How accurate is this year to month conversion? +
The factor used is 12, carried at full double precision. Where a unit has an exact legal definition the factor is exact rather than approximate. Rounding is applied only to the displayed result, so the answer is never a calculation done on an already-rounded number.
Is there a quick way to estimate yr to mo in my head? +
Multiply by 12. That matches the true factor of 12 exactly, so no adjustment is needed for a mental estimate.