Makeup Expiration Calculator
Use this makeup expiration calculator to find out when an opened product should be thrown away. Most cosmetics carry a “period after opening” (PAO) symbol — a small open-jar icon with a number of months. Enter the date you opened the product and its PAO, and the calculator gives the replace-by date and how long you have left.
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Calculate your replace-by date
Enter values above and press Calculate to see your result.
Formula used
The replace-by date is simply the open date plus the period after opening:
Replace by = Date opened + PAO months
The PAO is printed on the packaging as an open-jar symbol with a number followed by “M” (months). It applies from the moment you first open the product, not from the date of purchase or manufacture.
Worked examples
Foundation (12M). Opened 1 Jan → replace by 1 Jan next year.
Mascara (6M). Opened 1 March → replace by 1 September.
Sealed but old. Unopened products follow their own expiry date or a 2–3 year shelf life, not the PAO.
How to use this calculator
- Find the open-jar (PAO) symbol on the packaging and read the number of months.
- Enter the date you opened the product.
- Enter the PAO in months.
- Press Calculate to see the replace-by date, days remaining, and status.
- Write the open date on the product so you don't have to guess later.
Typical period after opening (PAO)
Common ranges — always check your product's own symbol.
| Product | Typical PAO | Why |
|---|---|---|
| Mascara / liquid eyeliner | 3–6 months | Highest infection risk; near the eye |
| Liquid foundation / concealer | 6–12 months | Water content invites bacteria |
| Cream blush / lipstick | 12–18 months | Some preservatives, applied to skin/lips |
| Powders (eyeshadow, blush) | 12–24 months | Dry; slower to spoil |
| Skincare / serums | 6–12 months | Actives degrade once opened |
| Perfume | 24–36 months | Alcohol preserves; store cool and dark |
Discard sooner if a product changes smell, colour, or texture, or separates.
Who should use this calculator
Anyone who wants to keep their makeup bag safe and avoid using products past their prime. It's especially useful for eye products, where expired formulas carry a real infection risk, and for anyone decluttering a collection.
Why period after opening matters
Once opened, products are exposed to air, moisture, and bacteria from skin and applicators. Preservatives only hold this off for so long. Using a product past its PAO won't always cause harm, but the risk of irritation, breakouts, and — for eye products — infection rises. Mascara is the highest-risk item because the wand repeatedly carries bacteria back into a dark, moist tube.
Signs to replace makeup early
- Smell has turned sour, chemical, or “off”.
- Texture has separated, dried, or gone clumpy (especially mascara).
- Colour has shifted or darkened.
- Irritation after use — stop immediately.
Limitations of this calculator
This counts months from your open date; it can't assess how a product has actually been stored or used. Heat, sunlight, double-dipping, and water contamination all shorten real life. Trust your senses — if a product looks, smells, or feels wrong, replace it regardless of the date. This tool is general guidance, not medical advice.
Frequently asked questions
What does the open-jar symbol mean?
It's the period after opening (PAO): the number of months a product stays good once opened — for example “12M” means twelve months. Counting starts when you first open it.
How long does mascara last after opening?
Usually 3–6 months. It carries the highest infection risk because the wand reintroduces bacteria; replace it on the early side and never share it.
Is PAO the same as an expiry date?
No. Unopened products have a shelf life or expiry date; the PAO applies only after opening. Use whichever comes first.
Can I use makeup past its PAO?
It's not recommended, especially for eye and liquid products. If a product is past PAO or looks, smells, or feels off, replace it.
How can I track when I opened something?
Write the open date on the product with a marker or a small sticker, then use this calculator whenever you want to check it.