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Weeks Between Dates Calculator
Find how many weeks separate two dates, shown as whole weeks plus leftover days and as a decimal. Handy for pregnancy weeks, training plans, school terms and project schedules.
- Weeks (decimal)
- 37.43
- Days
- 262
- Years, months, days
- 8 months, 19 days
Saved setups
Save a set of inputs you reuse — your usual rate, your loan, your room sizes — and load it back in one tap.
Your recent calculations
Results you calculate here are kept on this device so you can come back to them.
Formula
Weeks = days between ÷ 7
Leftover days = days between mod 7
How to use it
- Enter the start and end dates.
- Read the whole weeks and days, or the decimal value for spreadsheets.
Worked examples
January 1 to June 30, 2026
- Weeks between
- 25 weeks, 5 days
- Days
- 180
- Weeks (decimal)
- 25.71
January 5 to October 12, 2026
- Weeks between
- 40 weeks
- Days
- 280
Weeks in common spans
A common year is 52 weeks and 1 day; a leap year is 52 weeks and 2 days. A full-term pregnancy is counted as 40 weeks (280 days) from the first day of the last period. A US school year is typically about 36 weeks of instruction.
Questions people ask
How many weeks are in a year?
52 weeks plus one day, or plus two days in a leap year — about 52.14 weeks.
How many weeks are in 6 months?
About 26. January 1 to June 30, 2026 is 25 weeks and 5 days.
Related calculators
Days Between Dates CalculatorDays, weeks, months and business days between two dates.Months Between Dates CalculatorWhole months and leftover days between two dates.Week Number CalculatorThe ISO week number for any date, with its start and end.Due Date CalculatorEstimated due date from your last period, conception date or IVF transfer.