Food Expiration Date Guide: "Best By" vs "Use By" vs "Sell By" — What Do They Actually Mean?

You open the fridge, grab the yogurt, and notice it says "Best By March 10." Today is March 12. Is it still safe? Should you throw it out? The answer depends entirely on what that label actually means — and that is where most people get confused. This food expiration date guide breaks down every label type so you can make confident, safe decisions about the food in your kitchen.

The Core Problem: There Is No Federal Expiration Date Standard

Here is something most people do not know: with the exception of infant formula, there is no federal law in the United States requiring food manufacturers to put expiration dates on products at all. The dates you see on packaging are voluntary, and there is no standardized meaning across the industry. "Best By" on a box of crackers from one manufacturer may mean something completely different than "Best By" on a box from another.

This patchwork system causes enormous confusion — and enormous waste. According to the USDA, up to 30% of the food supply is lost or wasted at the retail and consumer level, and date label confusion is a significant driver. Using an app like Shelf Life to track your actual purchase and open dates — rather than relying on vague printed labels — is a far more reliable approach.

"Best By" — Quality, Not Safety

A "Best By" date is the manufacturer's estimate of when a product will be at peak quality in terms of flavor, texture, and aroma. It is not a safety deadline. A bag of chips that is two weeks past its "Best By" date might be slightly stale, but it will not make you sick. The same goes for most canned goods, cereals, dry pasta, crackers, and condiments.

• Safe to eat past this date: Yes, in most cases
• Quality may decline: Yes
• Means the food will cause illness: No

High-acid canned goods (tomatoes, citrus) typically stay safe 12–18 months past the "Best By" date. Low-acid canned goods (beans, vegetables, meat) can last 2–5 years past it. Trust your senses — if it smells, looks, or tastes off, discard it regardless of the date.

"Use By" — The One That Actually Matters for Safety

A "Use By" date is the only label that directly relates to food safety. This date is typically found on highly perishable items like fresh deli meats, refrigerated ready-to-eat foods, and some dairy products. The FDA and USDA recommend treating "Use By" dates as hard deadlines — do not consume the product after this date, even if it looks and smells fine.

• Safe to eat past this date: No — discard it
• Risk of harmful bacteria: Higher than with other label types
• Applies to: Deli meats, some cheeses, ready-to-eat refrigerated foods

Infant formula is unique in that it has a federally mandated "Use By" date — the only product in the U.S. where this is legally required.

"Sell By" — For the Store, Not for You

A "Sell By" date is an inventory management tool for retailers. It tells store staff how long to display a product for sale. It has nothing to do with when the food becomes unsafe to eat. Milk labeled "Sell By March 15" is typically still perfectly good to drink 5–7 days after that date if it has been properly refrigerated.

• Intended audience: Store staff, not consumers
• Means the food is unsafe after this date: No
• Rule of thumb: Add 3–7 days for most refrigerated items

"Freeze By" and "Pack Date" Labels

Some products carry a "Freeze By" date, which is a recommendation for when to move the item to your freezer to maintain best quality. This is common on meat and poultry. A "Pack Date" (often seen on canned goods and some produce) tells you when the product was packaged, which can help you calculate freshness but is not a direct safety indicator.

How to Use These Labels Practically

A simple decision framework for food expiration dates:

• "Use By" has passed: Discard it. No exceptions.
• "Best By" has passed: Inspect with your senses. If it looks, smells, and tastes fine, it is almost certainly safe to eat.
• "Sell By" has passed: Check refrigerator storage guidelines (see our fridge storage guide) and use your judgment.
• No date at all: Track your purchase date and use standard storage timelines.

The Better Way to Track Freshness

Rather than squinting at faded ink on packaging, the most reliable approach is to track when you actually bought or opened something. Shelf Life lets you log items by barcode scan, automatically applies smart expiry windows based on the food type, and sends you expiry alerts before food goes bad — so you are making decisions based on real storage time, not marketing labels.

Ready to take the guesswork out of your kitchen? Start tracking for free and see the difference a smart system makes.