Convert Weeks to Days
Convert weeks to days (and back) with precision control and batch mode. Free, client-side, instant, secure.
Convert between weeks and days using the trivial 7× factor (calendar weeks are exactly 7 days everywhere - no leap weeks, no DST drift for week-length math). Bidirectional with optional batch mode and fractional breakdown into days/hours/minutes.
How to Use Convert Weeks to Days
- Type a number of weeks. The tool multiplies by 7 - no calendar awareness needed because weeks are exactly 7 days everywhere.
- For fractional weeks, the breakdown line shows the equivalent days/hours/minutes (1.5 weeks = 10 days 12 hours).
- Swap to convert days to weeks (divide by 7).
- Enable batch mode to paste many values, one per line. The output mirrors row-by-row; bad rows show
ERROR: ....
Frequently Asked Questions
Why doesn’t this need a calendar?
Because a week is defined as exactly 7 days everywhere – there’s no calendar variation, no leap weeks, no daylight-saving drift in week-length math. Months and years vary; weeks and days don’t.
What about ISO weeks?
The ISO 8601 “week of the year” varies between 52 and 53 weeks per year, but each individual ISO week is still exactly 7 days. So N weeks × 7 = N × 7 days regardless of which weeks you mean.
Does daylight saving affect this?
No. DST changes wall-clock time (one day in spring is 23 hours, one day in autumn is 25 hours), but the “day” unit in week-length math is the abstract 24-hour day. If you need DST-aware calculations, use a calendar-aware datetime tool with timezone support.
What’s the breakdown line?
For fractional values, it splits the result into whole days + leftover hours + leftover minutes. 1.5 weeks = 10.5 days = 10 days, 12 hours. 0.001 weeks = 0.007 days = 0 days, 0 hours, 10 minutes 4 seconds (approx).
What happens with negative input?
Rejected with an explicit error. Negative durations are usually a sign of upstream calculation errors. If you have a directional duration (e.g., “3 days before”), handle the sign at your level.
What about non-numeric input?
Rejected. Now abc shows Error: Not a valid number: "abc".
How precise is the output?
Up to 6 decimal places. Beyond that, floating-point error makes additional precision meaningless. For exact rational results, multiply by 7 manually – no rounding involved for integer weeks.
Is text uploaded?
No. Everything runs in your browser with JavaScript – nothing is sent to a server, logged, or stored, and the tool keeps working offline once the page has loaded.
What’s batch mode for?
Converting a list of values at once – paste a column from a spreadsheet, get a column back. Empty lines are preserved; bad lines show inline errors so you can fix them.
Can I convert weeks to years?
Not in this tool. Year length varies (365 or 366 days) so any weeks-to-years conversion needs to pick a definition (365.25 average? exact calendar?). Use a dedicated weeks-to-years tool with documented assumptions.