Expiration Date Calculator
Determine when a product expires, plus how long it remains usable after opening, to manage pantry and medicine cabinets.
Manufacture date: Tuesday, November 25, 2025
Expiration date: Wednesday, November 25, 2026
Days until expiration: 365 day(s)
How to Use This Calculator
Enter the manufacture or production date
Find it on the packaging or invoice. This is your starting point for shelf-life calculations.
Specify shelf life
Choose whether the shelf life is in days, months, or years, then enter the number from product specs.
Track opened products
If you have opened the item, add the opened date and how long it stays fresh afterward.
Formula
Expiration Date = Manufacture Date + Shelf Life
Opened Use-by = Opened Date + Days After Opening
Days Remaining = Expiration Date − Today
Example: Manufactured 2025-05-01 + 12 months → Expires 2026-05-01. Opened 2025-11-10 + 7 days → Use by 2025-11-17.
Stay Ahead of Expiry
- Use this calculator to rotate pantry goods before they expire.
- Label opened condiments with the open date and discard-by window.
- Track medications with both manufacturer expiry and pharmacy-provided “discard after” dates.
- Create inventory spreadsheets for meal prep and emergency kits.
Frequently Asked Questions
What if I only know the best-before date?
Use it as the expiration date directly, and work backwards to estimate shelf life if needed.
Are shelf-life months exact?
Months vary in length; the calculator uses calendar month math, so expiry dates match real calendars.
Can I add storage temperature adjustments?
Not automatically. If storage shortens shelf life, reduce the shelf life input accordingly.
Is this safe for baby formula?
Use manufacturer guidelines first. This calculator helps you plan but doesn’t replace official safety advice.