How many weeks are in a month?
Why calendar months do not equal exactly four weeks.
The arithmetic
Four weeks contain 28 days. Every month has at least four weeks, but most add two or three days, and leap-year February adds one.
Calendar rows
A displayed month can occupy four, five or six week rows depending on its length, starting weekday and whether the calendar begins Sunday or Monday.
Monthly planning
Do not multiply a weekly rate by four to estimate every month. Use actual dates or an annualized average when precision matters.
Related month guides
- How many days are in each month? — A complete guide to 28-, 29-, 30- and 31-day months.
- How many working days are in a month? — Count weekdays and adjust for holidays, leave and local schedules.
- How to read and build a monthly calendar — Create an accessible month grid with correct weekday alignment.