How many weeks in a month

One month is 4.348125 weeks here: the average month of 30.436875 days, which is the Gregorian year of 365.2425 days divided by twelve, then divided by seven. No month is that length. Months run 28, 29, 30 or 31 days, so in weeks they are exactly 4, or 4 weeks and 1, 2 or 3 days. A unit converter can only offer the average, so this result is an average rather than a conversion: right over a run of months, and wrong for any single one by up to three days.

Worked through: 1 month x 4.348125 = 4.34812 week.

Going the other way, one week is 0.2299841886 months.

For mental arithmetic: Multiply by 4.35. Use 4.33 if you are matching payroll's 52 weeks over 12 months.

'Four weeks in a month' is the most expensive rounding in household budgeting. Only a 28-day February is exactly four weeks; every other month is longer, and on average a month is 4.35 weeks. A weekly cost multiplied by four to get a monthly one therefore undercounts by about 8%, which on rent paid weekly is roughly a month's worth over a year. Payroll uses a slightly different average: weekly pay times 52, divided by 12, gives 4.333 weeks a month, because 52 weeks is 364 days rather than 365.24. The gap between 4.333 and 4.348 is the extra day or so a year that weekly schedules gain against the calendar. Some retailers avoid the problem entirely with a 4-4-5 calendar, which splits each quarter into thirteen whole weeks.

Precision is worth matching to the input. A measurement given as 0.1 month carries one or two significant figures, and reporting its conversion to six implies a precision the original never had.