Weeks Calculator
Calculate weeks between dates
Frequently Asked Questions
How do I calculate the number of weeks between two dates?
Enter start and end dates. The calculator divides the total days by 7 to get complete weeks plus remaining days. From January 1 to March 15, 2025 = 10 weeks and 3 days (73 days total).
Can I add weeks to a date?
Yes. Enter a start date and number of weeks. Adding 6 weeks to January 1 = February 12. Each week adds exactly 7 calendar days. This is useful for project planning, pregnancy tracking, and recurring schedules.
How many weeks are in a year?
A regular year has 52 weeks and 1 day (365 / 7 = 52.143). A leap year has 52 weeks and 2 days. ISO week numbering assigns 52 or 53 weeks depending on how the year starts and ends.
How is the weeks calculator used in pregnancy?
Pregnancy is tracked in weeks from the last menstrual period (LMP). Full term is 40 weeks. Enter your LMP date to see your current week. Week 12 = end of first trimester, week 28 = third trimester begins.
What is the difference between calendar weeks and work weeks?
Calendar weeks are 7 days (Monday-Sunday). Work weeks are typically 5 days (Monday-Friday). 4 calendar weeks = 28 days = 20 work days. For work-week calculations, use the Business Days Calculator instead.