Expiration Date Calculator — Shelf Life & Best Before
Find out when a food, medicine, or household product expires. Choose from pre-filled shelf lives for common items or enter a custom duration, then see the expiration date, how many days remain, and a timeline of the product's life.
Common item (optional shortcut)
days
How does this calculator work?
Expiry date = start date + shelf life days. Enter the manufacture, purchase, or open date and the shelf life to get the expiration date, days remaining, and a shelf-life timeline. Pre-filled values for common foods and medicines are editable estimates — the label on your product always takes precedence.
Formula
How this is calculated
Expiration dates are calculated by adding the manufacturer's stated shelf life to a reference start date — which can be the production date, the date of purchase, or the date the packaging was opened, depending on the product. This calculator uses days as its unit, working from any ISO-format date you enter (YYYY-MM-DD).
The pre-filled shelf lives for common items are general estimates based on typical storage conditions (refrigeration for dairy and meat, cool dry storage for dry goods). They are provided as a starting point and may differ substantially from what is printed on your specific product. Actual shelf life is affected by storage temperature, humidity, packaging integrity, and whether an item has been opened or frozen — always follow the date on the label.
"Best before" and "use by" are not the same. "Best before" is a quality indicator: the food may be safe after that date but may have declined in taste or texture. "Use by" is a food-safety deadline set by the manufacturer; consuming food past its use-by date carries a genuine risk of illness. Labels on packaging legally supersede any estimate from this calculator.
Frequently asked questions
"Best before" indicates peak quality — the food may still be safe after this date. "Use by" is a food-safety date and should not be exceeded, even if the food looks and smells normal. Always respect use-by dates.
Use the day you opened the item as the start date and enter the "once opened, consume within X days" guidance from the label as the shelf life. Many dairy products, sauces, and cold cuts have a much shorter shelf life once opened than before.
They are typical estimates for average storage conditions and are intended as rough guidance only. Actual shelf life depends on temperature, humidity, packaging, and whether the item has been opened. Always check the label on your product and use that date.
TG we-Calculate Editorial Team. (2026). Expiration Date Calculator — Shelf Life & Best Before [Online calculator]. TG we-Calculate. https://we-calculate.com/calculator/expiration-date-calculator
TG we-Calculate Editorial Team. "Expiration Date Calculator — Shelf Life & Best Before." TG we-Calculate. 2026. https://we-calculate.com/calculator/expiration-date-calculator.
TG we-Calculate Editorial Team, "Expiration Date Calculator — Shelf Life & Best Before," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/calculator/expiration-date-calculator
@misc{wecalculate_expiration_date_calculator, title = {Expiration Date Calculator — Shelf Life & Best Before}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/calculator/expiration-date-calculator}}, year = {2026}, note = {TG we-Calculate} }
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