12 months to days
365.24 d
12 mo = 365.24 d.
days
365.24d
12 mo = 365.24 d
In short
How many days is 12 months?
12 mo = 365.24 d. 1 month = 30.436875 days, so the working is 12 × 30.436875 = 365.24.
The working
The factor below is an exact definition rather than a measurement, so nothing is approximated in the arithmetic. The only rounding on this page happens where a number is displayed.
1 month = 30.436875 days 12 × 30.436875 = 365.24
How much precision do you need?
Each row is the same answer cut at a different number of decimals, with what that choice costs you. Pick the shortest row whose error is smaller than whatever you are measuring with.
| Rounded to | Answer (d) | Off by |
|---|---|---|
| Whole number | 365 | −0.24250 |
| 1 decimal | 365.2 | −0.04250 |
| 2 decimals | 365.24 | −0.00250 |
Round trip: take 365.24 d back the other way and you land on 11.9999 mo — a drift of 0.0001 mo. That gap is the rounding, not the conversion.
What 12 mo looks like
12 mo
Twelve months is 365.2425 days, the calendar year the leap rule averages to.
Frequently asked questions
What is 12 months in days?
12 months is 365.24 days. 1 month = 30.436875 days, so the working is 12 × 30.436875 = 365.24.
How accurate is 365.24 d?
Rounding to 365.24 d and converting straight back gives 11.9999 mo, a drift of 0.0001 mo from the 12 you started with. The factor itself is exact; every bit of that difference comes from the rounding, not the conversion.
Nearby values
Any value at all
Months to Days Converter
Convert months to days — the average month is 30.44 days, and no actual month is.
Open the months to days converter →