As per Gregorian calendar, there are 52.18 weeks in a year of 365 days. So approximately number of weeks in a month is close to 4.358125 weeks. But this is just an approximate calculation because when we assume a month with 4 weeks, then the result will be 4 x 7 = 28 days. Except for the month of February in the non-leap year, this calculation wont be taken into account. Use this online Weeks To Months calculator to convert the number of weeks into months.