Week Calculator | Calculate Weeks From/Before Today & Any Date
Calculate dates X weeks from today or before today. Perfect for planning, deadlines, countdowns, and scheduling.
The Week Calculator is a specialized tool for individuals and professionals who manage schedules in weekly blocks. Whether you are tracking a pregnancy, planning a multi-phase project, or determining an ISO week number, this calculator provides instant clarity on weekly durations and future dates.
Features of the Week Calculator
Week Difference
Calculate the total number of weeks and remaining days between two dates, ideal for long-term tracking.
Add/Subtract Weeks
Find a future or past date by adding or subtracting a specific number of weeks to your starting point.
Week Numbers
Identify the current week number of the year or find the ISO week number for any specific date.
Pregnancy Tracking
Track pregnancy progress by weeks and days to determine trimesters and estimated due dates.
Project Sprints
Organize agile sprints or academic terms by dividing time into consistent 7-day increments.
Work Week Count
Calculate the total number of full or partial work weeks excluding specific holidays or weekends.
Common Week Calculations
| Calculation Type | Example | Result | Use Case |
|---|---|---|---|
| Total Weeks | Jan 1 to June 1 | 21 weeks, 4 days | School semesters |
| Add Weeks | Today + 12 weeks | Future Date | Subscription renewal |
| Project Length | 52 weeks from start | 1 Year anniversary | Contract duration |
How to Use the Week Calculator
Step-by-Step Guide
- Choose Mode: Select "Difference" to find time between dates or "Add/Subtract" to find a specific date.
- Enter Dates: Input your start date and either an end date or the number of weeks.
- Specify Fractional Weeks: You can enter decimal weeks (e.g., 2.5 weeks) for more precise addition.
- Calculate: The tool will instantly convert the duration into weeks, days, and hours.
- Check Week Number: View the "Current Status" section to see where the selected date falls in the yearly calendar.
Weekly Conversion Reference
= 168 hours
= 10,080 minutes
= 3 months (approx)
= 91 days
= 365.25 days
= 8,766 hours
Weekly Organization Methods
ISO 8601 Standard
The international standard where Week 01 is the week containing the first Thursday of the year. Weeks always start on Monday.
North American System
Commonly used in the US, Canada, and Japan, where the week typically begins on Sunday for calendar purposes.
Key Considerations
- A "Standard Year" has 52 weeks and 1 day (or 2 days in a leap year).
- ISO weeks are strictly 7 days, even when transitioning between years.
- Payroll "Bi-weekly" cycles occur 26 times a year, while "Semi-monthly" occurs 24 times.
- Pregnancy weeks are usually calculated from the first day of the last menstrual period (LMP).
Frequently Asked Questions
What is the "Week Number" right now?
The week number depends on your region. Most of the world follows the ISO 8601 standard (starting Monday), while others start the count on the first Sunday of January. This calculator provides both for accuracy.
How many weeks are in a work year?
A typical work year is considered 52 weeks. If you work 40 hours per week, this equates to 2,080 working hours per year, before accounting for holidays and vacation time.
How do I calculate weeks for a project deadline?
Select your project start date and add the number of weeks allotted. If your project is "10 weeks," the calculator will provide the exact calendar date 70 days from the start.
This week calculator is designed for general scheduling and informational purposes. For financial interest periods or strict legal timelines, please ensure your calculations align with the specific "day count convention" required by your institution.