How to Calculate Food Product Expiry Dates (Use-By vs Best Before)

Accurate expiry dates are an essential part of running a compliant food manufacturing business. Whether you’re making hot sauce in your kitchen or scaling a small-batch bakery, understanding your labeling obligations protects your customers — and keeps your business on the right side of the law.

This guide covers what expiry dates actually mean, how to calculate them for your food products, what the FDA requires, and how to track expiry information across every batch you produce.

Last updated: April 2026.

What’s the difference between a use-by date and a best before date?

A use-by date is the safety deadline after which food should not be consumed; a best before date guarantees quality, not safety.

In the food industry, these dates are often grouped under the umbrella term “shelf life.” Most food safety regulations require one or the other to be clearly labeled on each product you sell.

Use-by date — the date by which the product can be safely consumed, assuming it’s been stored and handled correctly. Once a use-by date passes, the product is typically discarded. Use-by dates are generally required on foods that spoil quickly, like meat, fish, and some dairy.

Best before date — the date up to which the manufacturer guarantees the product’s quality. The product can technically be consumed after this date, but key characteristics like colour, flavour, or texture may have degraded. Best before dates are typically used for longer-shelf-life items like canned goods, dry pantry staples, or baked goods with preservatives.

The distinction matters for labeling purposes. Selling a product past its use-by date is illegal in most jurisdictions. Selling a product past its best before date is generally a quality issue rather than a safety one — but you still need to be accurate.

Why is it important for food manufacturers to calculate accurate expiry dates?

Accurate expiry dates protect your customers from foodborne illness, protect your reputation from early-spoilage complaints, and keep your business legally compliant.

Getting them wrong creates liability — not just a quality problem. Accurate expiry date calculation protects your business on three fronts:

1. Food safety — if your product spoils before the labeled date, it can make customers sick. This is especially serious for anything containing meat, fish, eggs, or dairy, where foodborne illness risks are highest.

2. Customer trust — a product that goes off early damages your reputation fast. For small-batch food businesses, word of mouth cuts both ways.

3. Legal compliance — in most countries and US states, selling food past its use-by date is a legal violation. Getting your dates wrong isn’t just a quality problem; it’s a liability.

FDA labeling requirements for food expiry dates

In the United States, there is no single federal law that mandates expiry date labeling on most food products — with the notable exception of infant formula, which must carry a “use by” date under 21 CFR Part 107.

For most other foods, date labeling is at the manufacturer’s discretion. However, the FDA strongly encourages the use of standardized language to reduce consumer confusion. The FDA and USDA jointly recommend using “Best if Used By” as the standard phrase for quality-based dates, distinct from safety-based labels. The FDA’s Food Labeling Guide is the primary reference for US producers working through their labeling obligations.

A few important points for small-batch food producers in 2026:

• No federal mandate for most foods — but state regulations vary. Some states require date labeling on specific categories (deli meats, fresh bakery goods, etc.). Check your state’s department of agriculture rules.
• Cottage food laws — if you’re operating under a cottage food exemption, your labeling requirements may differ from commercial producers. Most cottage food laws require ingredient lists and allergen disclosures; some require best-before dates. Again, check your specific state’s exemption.
• FSMA compliance — if you’re covered by the FDA Food Safety Modernization Act (FSMA), you’ll need Hazard Analysis and Risk-Based Preventive Controls (HARPC) documentation. Shelf life determination is part of this process. Familiarising yourself with Good Manufacturing Practice (GMP) is a useful starting point — the same documentation requirements that cover your batch records also cover shelf life determination.

Even where date labeling isn’t strictly mandated, including a best before or use-by date is good practice. It sets clear customer expectations and demonstrates you’ve actually thought through your product’s shelf life — which matters when pitching to retailers or wholesale buyers.

How do I calculate expiry dates for my food products?

Calculating a food product’s expiry date starts with analysing your raw materials and ends with formal shelf life testing through a commercial lab.

Here’s how to approach it:

Step 1 — Know the shelf life of each raw material. Your finished product can only be as stable as its most perishable ingredient. Review the expiry information for every raw material you use and understand how it behaves under your production conditions. If you’re using a fresh herb paste that expires in 14 days, your finished product can’t reasonably claim a 6-month shelf life.

Step 2 — Map your production and storage conditions. Temperature, humidity, pH, water activity, and packaging type all affect how quickly a product degrades. You need to understand the microbiological and chemical characteristics of every ingredient, and how your manufacturing process affects them. Any potential hazard — contamination risk, temperature exposure, moisture ingress — should be documented and factored into your estimate.

Step 3 — Generate an initial estimate. Based on your ingredient analysis and storage conditions, develop a preliminary shelf life estimate. This is your hypothesis — you’ll test it in the next phase. Resist the temptation to borrow numbers from competitor products. Their materials, production environment, and formulations almost certainly differ from yours.

Step 4 — Use an expiry date calculator for quick checks. For straightforward products, a food expiry date calculator can help validate your thinking. These tools are useful for ballparking dates based on ingredient data, but they don’t replace proper shelf life testing.

Step 5 — Label your products correctly. Once you’ve confirmed your shelf life through testing, label every batch accordingly. Include the date format your market expects (e.g., MM/DD/YYYY in the US, DD/MM/YYYY in Australia). Consistency matters — especially if you’re selling through retailers who have their own labeling requirements.

Step 6 — Keep records. Document every shelf life determination you make: the inputs, the methodology, the test results. If a product batch is ever called into question, you want to be able to trace it back to a specific calculation and test result quickly.

Shelf life testing

Once you have a preliminary estimate, the next step is formal shelf life testing. Most retailers require documented evidence of this testing before they’ll list your product. It’s not optional at commercial scale — it’s table stakes.

Shelf life testing is typically done in collaboration with a commercial food laboratory. Your product is tested for safety and quality markers at regular intervals throughout the proposed shelf life period. The Institute of Food Technologists (IFT) publishes guidance on shelf life principles that’s useful background reading before commissioning a study.

For example: if you estimate a 6-month shelf life, the lab will test at Day 0, Day 1, Day 7, Day 14, Day 30, Day 60, Day 90, and so on until the 6-month mark is passed. The lab will ask about your manufacturing conditions, packaging, and intended storage temperatures — all of which inform the test parameters.

Standard markers tested in shelf life studies:

• pH
• Water activity
• Salmonella
• E. coli
• Staph. aureus
• Aerobic plate count
• Listeria
• Mould

For each marker, the lab produces a report summarising findings at each time point. If contamination is detected early — say, on Day 1 — the test stops and a new sample is required.

The cost of shelf life testing varies by product category and test duration. Budget anywhere from a few hundred to a few thousand dollars depending on the number of markers and the length of the study.

Testing your product expiry date

Getting an expiry date confirmed isn’t a one-time exercise. You’ll need to retest when:

• You change any ingredient in your formulation
• You update your production process
• You change batch sizes or packaging formats
• You introduce new manufacturing equipment (a new mixer, a different sealing machine)
• A significant amount of time has passed since your original test

The goal is to make sure your labeled dates remain accurate as your business evolves. A product that tested well two years ago may behave differently if you’ve since switched to a new supplier for a key ingredient.

Tracking expiry dates across batches

Calculating an accurate expiry date is only half the job. The other half is tracking it — across every batch, every lot of raw materials, and every finished product that leaves your facility.

This is where most small-batch food producers run into trouble. A spreadsheet can hold a date. It can’t alert you when a lot is approaching expiry, automatically flag affected product batches when a material is recalled, or generate a traceability report in minutes when a retailer asks for one. For a broader look at building that traceability layer, our guide to food traceability for small producers covers the full system — from ingredient lot tracking through to recall readiness.

Specialised food manufacturing inventory software like Craftybase is built for exactly this — tracking expiry dates, purchases of materials, and manufacturing at the batch lot level.

Each lot of materials you purchase can be assigned a unique code alongside an expiry date. When you manufacture a batch of finished product, those lots are associated with the manufacture record — so you know exactly which materials went into which batches. Expired lots can be flagged and discarded quickly.

A full traceability report can be generated for any product or order, making a recall response fast rather than frantic.

This connects directly to lot number tracking and batch tracking — both of which are part of a proper food safety record-keeping system. If you’re required to comply with FSMA or if you’re supplying to retailers who require traceability documentation, software that handles this automatically is far preferable to maintaining it manually.

For a broader look at managing a small-batch food operation, our guide on starting a food manufacturing business covers the full picture — from licensing through to production record-keeping.

Frequently Asked Questions

Running a compliant food business means staying on top of both the science and the record-keeping. Knowing how to calculate your expiry dates is step one. Tracking them accurately — batch by batch, lot by lot — is what keeps you protected when it matters most.

If you’re ready to move beyond spreadsheets, Craftybase’s food manufacturing software handles lot tracking, batch records, and expiry management in one place.