How do I count weeks between two dates?

Find the total days between the dates and divide by 7: the whole part is full weeks and the remainder is leftover days. From 2024-01-01 to 2024-02-15 is 45 days = 6 weeks and 3 days, or about 6.43 weeks.

weeks = total days ÷ 7. Because a week is always exactly seven days, it's a straight division — unlike months, which vary from 28 to 31 days. 28 days is exactly 4 weeks; 45 days is 6 weeks 3 days.

How many weeks is a year?

A common year of 365 days is 52 weeks and 1 day; a leap year of 366 days is 52 weeks and 2 days. So a year is just over 52 weeks, never exactly 52, which is why the same calendar date shifts forward by one or two weekdays each year.

Does the order of the dates matter?

No. If you enter the later date first, the calculator swaps the two so the result is always a positive number of weeks. The count of weeks and days is the same either way.

Can I use it for pregnancy weeks?

Yes. Enter the start date (such as the last menstrual period) and today's date to see how many weeks and days have passed. It's also handy for sprint planning, notice periods and any schedule counted in weeks.

Weeks Between Dates Calculator

Enter two dates to get the number of weeks between them, with the leftover days, the decimal weeks, and the total days. A week is always exactly seven days.

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✓ Decimal weeks

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Weeks between dates — Quick answer

Divide the total days between the dates by seven.

weeks = total days ÷ 7 · remainder = leftover days

Worked example: 2024-01-01 → 2024-02-15 = 45 days = 6 weeks 3 days.

Examples

From → To	Days	Weeks
Jan 1 → Jan 29	28	4 wk
Jan 1 → Feb 15	45	6 wk 3 d
Jan 1 → Jan 1 (next yr, leap)	366	52 wk 2 d

A week is exactly 7 days — so this is a clean division, unlike months.

This calculator counts the weeks between two dates by finding the total days and dividing by seven: the whole part is full weeks and the remainder is leftover days. It also shows the result as decimal weeks and the total days. Because a week is always exactly seven days, the maths is a clean division.

Reviewed: June 20, 2026 · Author: Naveen P N, Founder — AI Calculator · Verified against: day-count ÷ 7, recomputed in code.

How it works

Total days

days = end − start (whole days)

Weeks

full weeks = ⌊days ÷ 7⌋ · leftover = days mod 7

Count the whole days between the two dates, then divide by seven. The integer result is the number of complete weeks and the remainder is the extra days. Decimal weeks is simply days ÷ 7. Unlike months — which vary from 28 to 31 days — every week is exactly seven days, so no calendar adjustment is needed.

Worked examples

Jan 1 to Jan 29 (same year):

Exact

28 days ÷ 7 = 4 weeks, 0 days

Jan 1 to Feb 15:

With remainder

45 days = 6 weeks and 3 days (≈ 6.43 weeks)

A full leap year, Jan 1 to next Jan 1:

Just over 52

366 days = 52 weeks and 2 days

So 28 days is exactly 4 weeks, 45 days is 6 weeks 3 days, and a leap year is 52 weeks 2 days — a year is always a touch more than 52 weeks.

Frequently Asked Questions

How do I count weeks between dates?⌄

Total days ÷ 7. Whole part = weeks, remainder = days. 45 days = 6 wk 3 d.

What is the formula?⌄

weeks = days ÷ 7. A week is always 7 days, so it's a clean division. 28 days = 4 weeks.

How many weeks in a year?⌄

365 days = 52 wk 1 d; leap 366 = 52 wk 2 d. Always just over 52.

Does date order matter?⌄

No — reversed dates are swapped so the answer is positive.

Use it for pregnancy weeks?⌄

Yes — start date to today gives weeks and days. Also for sprints and notice periods.

Weeks Between Dates Calculator

Weeks between dates — Quick answer