Months Between Dates Calculator

It counts complete calendar-month anniversaries first, then adds a fraction for the leftover days. A month is complete only when the same day of the month is reached, so January 15 to February 15 is one month and January 15 to February 14 is zero months. The leftover days are divided by the actual length of the current calendar month, so the fraction stays accurate whether that month has 28, 29, 30, or 31 days.

Calendar months are not all the same length, so dividing leftover days by a flat 30 would be wrong for February and the 31-day months. This tool scales the partial month by the number of days between the last anniversary and the next one (28 to 31 days). If you prefer the average-length convention, the result also shows months calculated as total days divided by 30.44, the mean Gregorian month.

Since February has no 31st, the anniversary of the 31st clamps to the last day of February. That makes January 31 to February 28 (or February 29 in a leap year) count as one full month. This matches how most date and loan calculators treat month-end rollovers.

No. The calculator always treats the earlier date as the start, so swapping the start and end dates gives the same number of months, weeks, and days. The result is never negative.

Whole months is the count of complete monthly anniversaries, shown alongside the leftover days (for example, 2 months and 5 days). Total months is that same span expressed as one decimal number, such as 2.16 months, which is useful for spreadsheets, contracts, or billing periods that need a single value.

Yes. Total days and weeks come from the exact calendar difference between the two dates, so any February 29 inside the range is counted. The Gregorian leap-year rule applies (every 4 years, except century years not divisible by 400).