Shelf Life Calculator
Work out the expiry date and days remaining from a production date and shelf life, with reverse calculation, week units and batch mode.
With the production date, back-calculates the total shelf life
Counted from the expiry date; leave 0 or empty to skip
Month-based shelf life follows calendar months and clamps to the last day of the month
Weekday
After-opening expiry
Shelf life length
Sorted by days remaining; batches expiring within 30 days are highlighted
Batch results update live and can be exported as text
How to Use
🗓️ Shelf Life Calculator
Enter the production date and the shelf life, and the tool gives the expiry date plus how many days are left or how far past due it is. The usual case is clearing out a fridge or a storage cupboard: feed in the dates on snacks, medicine and cosmetics and see which is about to expire.
Month-based shelf life follows calendar months rather than adding 30 days. January 31 plus one month lands on the last day of February, not 3 March, and 29 February plus a year becomes 28 February. That matches how a manufacturer means "12 months shelf life" and avoids the drift you get from day counting.
✨ Features
- Days, months or years as the shelf life unit
- Month and year addition clamps to the last valid day
- Shows the expiry date, days remaining and total shelf life in days
- Red when overdue, amber when expiring today
- Nothing leaves the browser
🚀 How to Use
- Pick the production date, or press Today
- Enter the shelf life and choose its unit
- The expiry date and remaining days appear
- Copy the date if you need it elsewhere
⚠️ Notes
- The package wins: the real expiry depends on how the maker counts; some print a best-before date outright
- Opening resets the clock: most food and cosmetics expire far sooner once opened; this tool models the sealed state
- Not medical advice: whether a medicine is still usable is a question for its leaflet and a pharmacist
- Local clock: days remaining use this device's date, so a wrong system clock or a different timezone shifts the result
New in v1.1.0
- Reverse mode: expiry date back to production date
- Week unit for shelf life
- Remaining-time progress bar
- 30-day warning and batch calculation
New in v1.2.0
- After-opening shelf life counted from the expiry date
- Weekday of the expiry date
- .ics export for calendars, with a one-day reminder
New in v1.3.0
- Back-calculation: fill both production and expiry dates to get the total shelf life in days, months and years
新增功能（v1.4.0）
- Batch calendar: one date per line (optionally with amount and unit), each expiry computed and sorted by urgency, 30-day highlight
Visual and functional fixes (v1.4.1)
- Fixed the shelf-life length row staying empty in forward mode and not refreshing