Months to Days Converter
Convert months to days — using the average month of 30.44 days, since real months vary. Results update as you type; exact factors shown.
One month (average, 30.4369 days) is 30.4369 days — see the exact factor, not a rounded rule of thumb.
How the months to days converter works
Time converts through the second. Minutes, hours, days and weeks are exact multiples. A month is taken as the Gregorian average (30.436875 days) and a year as the Gregorian average (365.2425 days = 31,556,952 s); calendar months and leap years vary from these averages.
The US uses customary units (US gallon, short ton, °F) in daily life; NIST SP 811 gives the exact SI factors.
Common time conversions
| From | To | Units |
|---|---|---|
| 1 mo | 30.4369 d | month (average, 30.4369 days) to days |
| 2 mo | 60.8738 d | month (average, 30.4369 days) to days |
| 3 mo | 91.3106 d | month (average, 30.4369 days) to days |
| 6 mo | 182.6213 d | month (average, 30.4369 days) to days |
| 9 mo | 273.9319 d | month (average, 30.4369 days) to days |
| 12 mo | 365.2425 d | month (average, 30.4369 days) to days |
| 18 mo | 547.8638 d | month (average, 30.4369 days) to days |
| 24 mo | 730.485 d | month (average, 30.4369 days) to days |
| 36 mo | 1,095.7275 d | month (average, 30.4369 days) to days |
| 48 mo | 1,460.97 d | month (average, 30.4369 days) to days |
| 60 mo | 1,826.2125 d | month (average, 30.4369 days) to days |
| 120 mo | 3,652.425 d | month (average, 30.4369 days) to days |
Units in this converter and their exact factors
| Unit | Symbol | One unit in seconds |
|---|---|---|
| millisecond | ms | 0.001 second |
| second | s | 1 second |
| minute | min | 60 second |
| hour | h | 3,600 second |
| day | d | 86,400 second |
| week | wk | 604,800 second |
| month (average, 30.4369 days) | mo | 2,629,746 second |
| year (365.2425 days) | yr | 31,556,952 second |
FAQFrequently asked questions about time conversion
How many days in a month?
Between 28 and 31. This uses the average of 30.44 days, a twelfth of the average year.
Why not just use 30?
Because that loses five days a year, which matters over any long period.
How many days is 3 months?
About 91 on average, though a specific three months can be 89 to 92.
When does the average mislead?
For anything contractual — count the actual dates with the days-between calculator instead.
Where these figures come from
- BIPM — The International System of Units (SI Brochure, 9th edition) — definitions of the base and derived units.
- NIST Special Publication 811 — Guide for the Use of the International System of Units — the exact conversion factors used here.
- National Institute of Standards and Technology (NIST) — United States's national measurement authority.
Last checked: September 2026. Conversion factors are fixed by definition and do not change with tax years or regulations.