# Days to Weeks Converter URL: https://speedycalculator.com/calculators/conversion/days-to-weeks/ Last updated: 2026-10-25 > Convert days (day) to weeks (week): 1 day = 0.14285714 week, so multiply by 0.14285714 or divide by 7. Both fields are editable, so you can also type in weeks and get days back. ## Inputs - Days (day) ## Results - Weeks ## Formula ``` 1 day = 0.14285714 week 1 week = 7 day week = day × 0.14285714 ``` ## Explanation 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 DaysWeeksWeeksDays7 day1 week1 week7 day10 day1.4285714 week2 week14 day14 day2 week5 week35 day21 day3 week10 week70 day28 day4 week20 week140 day30 day4.2857143 week50 week350 day60 day8.5714286 week100 week700 day90 day12.857143 week1,000 week7,000 day100 day14.285714 week180 day25.714286 week280 day40 week365 day52.142857 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). ## Worked example Inputs — Days: 100 day. Results — **Weeks = 14.28571429 week**. ## FAQ **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. ## Sources - [NIST Special Publication 811 – Guide for the Use of the International System of Units](https://www.nist.gov/pml/special-publication-811) - [NIST Handbook 44 Appendix C – General tables of units of measurement](https://www.nist.gov/pml/owm/nist-handbook-44-current-edition)