Seven days make a week, so divide by 7. Pregnancy, training plans and project schedules are often counted in weeks.
How to use the Days to Weeks Converter
- Type the number of days into the Days field. Decimals such as 50 are fine.
- Read the answer in Weeks – it updates as you type, with no button to press.
- To convert the other way, type into Weeks and the days are recalculated.
- Press Copy results to copy both values with the page title, or Copy link to share this exact conversion.
This page converts only day ⇄ week. Need a different unit? Use the general time converter, where you can choose any “from” and “to” unit.
How it works
Both units measure time, so they are always in the same ratio: one day equals 0.14285714 weeks. The calculator multiplies the number of days you type by 0.14285714 to give weeks, and when you type into the weeks field it divides by the same factor to give days. Because the ratio never changes, doubling the days always doubles the weeks. Results are calculated at full precision and rounded only for display (up to eight decimal places, with very large or small values shown in scientific notation).
How to convert days to weeks
- Write down the value in days, for example 100 day.
- Multiply by the conversion factor 0.14285714 (because 1 day = 0.14285714 week).
- 100 × 0.14285714 = 14.285714 week.
- To go back from weeks to days, divide by 0.14285714 – or multiply by 7.
day to week conversion table
| Days | Weeks | Weeks | Days |
|---|---|---|---|
| 7 day | 1 week | 1 week | 7 day |
| 10 day | 1.4285714 week | 2 week | 14 day |
| 14 day | 2 week | 5 week | 35 day |
| 21 day | 3 week | 10 week | 70 day |
| 28 day | 4 week | 20 week | 140 day |
| 30 day | 4.2857143 week | 50 week | 350 day |
| 60 day | 8.5714286 week | 100 week | 700 day |
| 90 day | 12.857143 week | 1,000 week | 7,000 day |
| 100 day | 14.285714 week | ||
| 180 day | 25.714286 week | ||
| 280 day | 40 week | ||
| 365 day | 52.142857 week |
What is a day?
A day is 24 hours or 86,400 seconds. Calendar days occasionally differ by one second when a leap second is added.
What is a week?
A week is 7 days. Pregnancy, training plans and payroll cycles are often counted in weeks.
Quick mental conversion
For a fast estimate, multiply days by about 0.14 to get weeks; the error is about 2.0%. Use the calculator above when you need the exact figure.
Common mistakes to avoid
Treating every month as 30 days or every year as 365 days in long calculations, and writing decimal hours such as 1.5 h as 1 h 50 min (it is 1 h 30 min).
Formula
1 day = 0.14285714 week1 week = 7 dayweek = day × 0.14285714Worked example
Inputs — Days: 100 day.
Results — Weeks = 14.28571429 week.
Frequently asked questions
How many weeks is 100 days?
About 14.29 weeks (14 weeks 2 days).
How many weeks in a year?
About 52.18.
How do I convert days to weeks?
Multiply the number of days by 0.14285714. For example, 100 day × 0.14285714 = 14.285714 week.
How do I convert weeks back to days?
Divide by 0.14285714 (or multiply by 7), or simply type the value into the weeks field above.
What is 10 day in weeks?
10 day = 1.4285714 week.
Is this conversion exact?
Yes. The factor comes from the official definitions of both units (NIST and the SI), so the only difference you may see is rounding in the last displayed digit.
Can I convert to other units on this page?
This page converts only between days and weeks. To pick any time unit, use the general time converter linked under Related calculators.
What formula does the Days to Weeks Converter use?
1 day = 0.14285714 week.