ES
Home › Time & Date › Expiration Date Calculator

Expiration Date Calculator

Work out when something expires from its manufacture or opening date. Add a shelf life or a period-after-opening (PAO) like 6M or 12M, and see the expiry date, days left and how much of the shelf life is used.

Last updated:

Start from

If the pack shows one, the earlier date is used.

Enter your values to see the result.
Advertisement
Advertisement

How to use the Expiration Date Calculator

  1. Choose the start: manufacture date with a shelf life, or the date you opened the product with its period after opening.
  2. Enter the date and the shelf life or PAO, e.g. 12 months for a 12M symbol.
  3. Add the printed expiry date if the pack has one; the earlier date is used.
  4. Read the expiry date, status and days left.
  5. Check the tables for milestones and other shelf lives.

How the expiry date is calculated

Days or weeks: expiry = start date + days (weeks × 7). Months or years: expiry = the same day of the month, that many months later (years × 12); if the month is shorter, the last day of the month is used (August 31 + 6 months = February 28 or 29).

When a product has both a calculated date and a printed date, the effective expiry is the earlier of the two. Percent used = (today − start) ÷ (expiry − start) × 100.

Period after opening (PAO) symbols

SymbolUse within after openingOpened Mar 1, 2026 → use by
3M3 monthsJun 1, 2026
6M6 monthsSep 1, 2026
9M9 monthsDec 1, 2026
12M12 monthsMar 1, 2027
18M18 monthsSep 1, 2027
24M24 monthsMar 1, 2028
36M36 monthsMar 1, 2029

Under EU cosmetics rules the PAO symbol is used for products that last longer than 30 months; products with a shorter life carry a "best before" date instead. Tip: write the opening date on the pack with a marker so you can check it later.

Frequently asked questions

How do I calculate an expiration date?

Add the shelf life to the start date. For months, move forward that many months to the same day: a product made on March 1, 2026 with a 24-month shelf life expires on March 1, 2028. If the target month is shorter, the last day of that month is used.

What does the 12M symbol on cosmetics mean?

The open-jar symbol with a number and M is the period after opening (PAO): the number of months the product stays good after it is first opened. 12M means use within 12 months of opening. Enter the date you opened it and 12 months to get the date.

What if the product has both a PAO and a printed expiry date?

Use whichever comes first. A cream opened in May with a 12M PAO but a printed expiry in October of the same year should be used by October. Enter the printed date and the calculator picks the earlier one.

What is the difference between 'best before' and 'use by'?

'Best before' is about quality: food may still be safe after it but can lose flavor or texture. 'Use by' is about safety and should not be exceeded. 'EXP' on cosmetics and many other products is the expiry date.

How can I find the manufacture date?

Many products print a manufacture date (MFG) next to the expiry date. Others use a batch or lot code that encodes the date in a brand-specific format; the manufacturer's customer service can decode it.

Does storage affect shelf life?

Yes. Heat, sunlight, humidity and contamination can shorten shelf life, while correct storage helps a product last to its date. The calculator gives the date from the label; always follow the product's storage instructions and discard anything that has changed color, smell or texture.

Are all the tools on FreeToolCabin tested for quality and accuracy?

Yes! Every tool on our site undergoes automated Q/A testing in real browser environments to ensure high precision, correct output, and zero errors. If you happen to spot a bug or have a suggestion, please contact us at [email protected] and our team will review it right away.

Related tools

Date CalculatorAdd days to a date or count days between dates.Days Until CalculatorCount down the days to any event.Days Between DatesCount days, weeks, months and business days between two dates.Notice Period CalculatorFind when a notice period ends: last working day and days remaining from any notice date.30 Days From TodayFind the date 30 days from today or any start date, with weekday and business days.60 Days From TodayFind the date 60 days from today or any start date, with weekday, business days and a calendar.Today's DateWhat is today's date? Live date in every format: ISO, US/EU, week number, Unix, Hijri, Hebrew.Business Days CalculatorCount working days between dates, excluding weekends and holidays.Day of the Week CalculatorFind the weekday of any date, with Zeller and Doomsday steps.Half Birthday CalculatorFind your half birthday date, the countdown to it and your age in halves.Retirement Date CalculatorFind the exact date you reach retirement age, with a live countdown.Age Difference CalculatorFind the exact age gap between two people in years, months and days.Day of the Year CalculatorFind the day number of any date (1–366), days left, ISO week and quarter, or turn a day number into a date.Anniversary CalculatorHow long you've been together, your next anniversary and traditional and modern gifts by year.Time Since CalculatorLive counter of the time since any date: years, months, days, hours, minutes and seconds.Excel Date ConverterConvert Excel serial numbers to dates and times and back, in the 1900 or 1904 date system.Baby Age CalculatorYour baby's exact age in days, weeks and months, plus the next monthly milestone date.Corrected Age CalculatorChronological and corrected (adjusted) age for preemies from the due date or weeks at birth.Date to Roman NumeralsConvert a date into Roman numerals (MM.DD.YYYY or DD.MM.YYYY) for tattoos and engravings.Dog Heat Cycle CalculatorPredict your dog's next heat dates and fertile window from the last heat and cycle length.Egg Incubation CalculatorCandling, lockdown and hatch dates for chicken, duck, quail, goose and turkey eggs.Fiscal Year CalculatorFind the fiscal year, quarter, period and week for any date and any fiscal year start.What Generation Am I CalculatorFind your generation from your birth year: Boomer, Gen X, Millennial, Gen Z or Gen Alpha.Harvest Date CalculatorExpected harvest date and window from planting date and days to maturity, with succession.Hebrew Date ConverterConvert Gregorian dates to Hebrew calendar dates and back, with after-sunset option.Nepali Date ConverterConvert AD dates to Bikram Sambat (BS) and back, with Nepali month names and numerals.Oil Change Due CalculatorFind your next oil change date and odometer reading from your last change and driving.Persian (Jalali) Date ConverterConvert Gregorian dates to the Persian Jalali (Shamsi) calendar and back, with month names.Seed Starting Date CalculatorWhen to start seeds indoors, transplant and direct sow each crop from your last frost date.90 Days From TodayFind the date 90 days from today or any date, with weekday, business days and a calendar.Animal Gestation CalculatorDue date, birth window and milestones for goats, sheep, pigs, cows, horses, rabbits and more.Horse Foaling Date CalculatorMare due date, foaling window and pregnancy care calendar from the cover date.Full Retirement Age CalculatorYour Social Security full retirement age, earliest claim date, 62 reduction and Medicare date.Maternity Leave CalculatorPlan maternity leave: start date, paid, PTO and unpaid weeks, and your return-to-work date.Medicare Enrollment Period CalculatorFind your Medicare Initial Enrollment Period, coverage start dates and sign-up deadlines.Sobriety CalculatorCount days, weeks, months and years sober from your sober date, with milestones and money saved.Tax Refund Date EstimatorEstimate when your IRS refund arrives by filing date, e-file or paper, deposit or check.PTO Holiday OptimizerFind the bridge days around US holidays that turn your PTO into the most days off in a row.Project End Date CalculatorTurn effort hours, team size and workdays into a completion date with a work-day calendar.Weekday CounterCount how many Mondays, Fridays or any weekdays fall between two dates and list them.Working Days Per Month CalculatorWorking days and hours for every month of a year, minus weekends and US federal holidays.What Year Was I Born CalculatorFind your birth year from your age, or from your age on any date, plus an age-by-year table.100 Days From TodayFind the date 100 days from today or any date, with weekday, business days and a calendar.180 Days From TodayFind the date 180 days from today or any date, with weekday, business days and a calendar.6 Months From TodayFind the date 6 months from today or any date, its weekday, day count and business days.Breast Milk Storage CalculatorUse-by date and time for pumped breast milk at room temp, in the fridge or freezer (CDC).Half Marathon Training Plan Generator10 to 16 week half marathon plan from your race date and level, with long runs, taper, paces and .ics.Horse Age CalculatorConvert horse years to human years, see the life stage, or get exact age from a foaling date.ISO 8601 Duration ConverterParse or build ISO 8601 durations like P1DT2H30M and convert them to seconds and h:m:s.Moving Checklist GeneratorEnter your move date and situation for a week-by-week moving to-do list with real dates.Home Inventory ListRoom-by-room home inventory with values, purchase dates, serial numbers and photos; print or CSV.Wedding Invitation Timeline CalculatorWhen to send save-the-dates and invitations, plus your RSVP deadline and final headcount date.Age Milestones CalculatorSee when you turn 10,000 days, 1,000 weeks, 500 months or 1 billion seconds old.Baby Leaps CalculatorFind your baby's 10 developmental leap weeks and fussy-period dates from the due date.Birthday Moon PhaseSee the moon phase on the night you were born and which future birthdays fall on a full moon.Chronological Age CalculatorExact age in years, months and days on a test date, using the borrow method for assessments.Day Length CalculatorHours of daylight for any place and date, change vs yesterday and a year chart by latitude.Easter Date CalculatorWestern and Orthodox Easter for any year, with Ash Wednesday, Good Friday and Pentecost.Famous Birthdays by DatePick any date to see famous people born that day, sorted by year, with ages and categories.Length of Service CalculatorYears, months and days of service from hire and end dates, plus your next work anniversary.Months Between DatesExact calendar months and days between two dates, decimal months and a month-by-month list.Who Was President When I Was BornEnter your birth date to see the US president and VP that day, plus every president in your lifetime.
See all 62 Date Calculators →