Lumiere
How to read the result
The calculator uses each category's typical period after opening — the manufacturer's statement of how long a product stays safe and effective once air first reaches it. It's shown on packaging as a small open-jar icon with a number inside, such as 12M.
Two rules make the answer more accurate:
- The number on your packaging beats the category average. If your moisturiser says
6Mand this page says 9, use 6. - Printed expiry dates override both. A product can pass its best-before date before you finish the PAO window, particularly sunscreen.
Packaging changes real-world life more than most people expect: the same formula in an open jar typically lasts noticeably less time than in an airless pump, because every use exposes it to air and introduces microbes. There's a fuller breakdown in the skincare shelf life chart.
When to discard regardless of the date
- It has separated and won't re-mix after shaking.
- The colour has shifted — especially a vitamin C serum going yellow, orange or brown.
- The texture is grainy, clumpy or suddenly pills under makeup.
- It smells rancid, sour or simply different.
- Anything is visibly growing in it.
Frequently asked questions
How does the calculator work?
You choose a product type and the date you opened it. The calculator applies the typical period-after-opening (PAO) for that category and returns the date it lapses plus the days remaining. If the packaging shows its own PAO — the little open-jar symbol with a number such as 6M or 12M — use that number instead; the manufacturer's figure always wins over a category average.
Does this send my data anywhere?
No. The calculation runs entirely in your browser. Nothing you enter is transmitted, stored or logged.
What if my product has no PAO symbol?
Products with a shelf life under 30 months carry a printed best-before date instead of a PAO symbol; use that. If there's neither, look for a batch code on the packaging — online batch-code checkers can often decode a manufacture date — and otherwise use the category default here.
My product isn't expired but looks strange. What now?
Trust your senses over the date. Separation that won't re-mix, a change in colour, graininess, or an off smell all mean discard it, whatever the calculator says.