Last Updated on December 12, 2025 by Melissa Lazaro

Understanding ISO 22000 Man-Day Calculations with Expert Insight

Here’s what I’ve noticed after helping companies prepare for ISO 22000 audits across different industries. The moment pricing comes up, everyone eventually asks the same question: “How many audit man-days do we actually need?” And honestly, the confusion makes sense. Certification bodies follow the same accreditation rules, yet their estimates often feel completely different.

This guide gives you the clarity that most companies wish they had earlier.
You’ll learn:

• How certification bodies calculate man-days.
• What affects the duration of Stage 1 and Stage 2 audits.
• How employee count, complexity, and risk level really play into the formula.
• A simple step-by-step calculator you can use to estimate your own audit duration.
• Practical ways to avoid unnecessary man-day increases.

In my experience, once organizations understand these elements, they make better scoping decisions, avoid inflated costs, and feel more confident negotiating with certification bodies.
Now that we’ve set the stage, let’s break down how the calculations actually work.

How Certification Bodies Determine ISO 22000 Audit Man-Days (Employee Count, Scope, Risk Level)

Certification bodies don’t pull man-day numbers out of thin air. They follow structured rules from accreditation documents like IAF MD 5. But the interpretation of those rules can vary, and that’s where the confusion begins.

Here are the main drivers behind your audit duration:

• Employee Count: The bigger the workforce, the more interviews, records, and processes the auditor must review.
• Process Complexity: A cold-chain distribution center isn’t the same as a high-risk cooked-food facility.
• HACCP Risk Level: High-risk products require deeper verification.
• Number of Product Categories: More categories equal wider HACCP coverage.
• Declared Scope: This is where many organizations unknowingly inflate their man-days.
• Multi-Site Operations: Additional locations add sampling requirements.

A quick story: One client listed every seasonal product variation in their initial scope. Once we clarified the true categories, the certification body reduced the required man-days significantly. Same company. Same system. A cleaner scope.

The key is accuracy—not oversharing or undersharing. Both can cost you.

Man-Day Requirements for Stage 1 vs Stage 2 (ISO 22000 Audit Duration Breakdown)

Stage 1 and Stage 2 serve very different purposes, and understanding that helps you prepare effectively.

Stage 1 Audit (Document & Readiness Review)

• Focuses on your Food Safety Management System documentation.
• Verifies HACCP structure, PRPs, and regulatory alignment.
• Identifies readiness gaps before the main audit.
• Typically requires fewer man-days but is still crucial.

Stage 2 Audit (On-Site Implementation Audit)

• This is the deep dive into your processes.
• Includes interviews, facility walkthroughs, HACCP validation, PRP verification, and record checks.
• The bulk of your man-days sit here.

Most certification bodies split man-days between Stage 1 and Stage 2 in a predictable pattern—but if Stage 1 is weak, you may need additional Stage 2 time.

Pro Tip: A strong internal audit and complete PRP documentation often prevent the need for extra man-days during Stage 2.

ISO 22000 Man-Day Table by Organization Size (Small, Medium, Large)

While certification bodies have flexibility, most follow established ranges. Here’s a simplified illustration to help benchmark your expectations:

Organization Size	Typical Man-Day Range	Notes
1–25 employees	Lowest range	Scope clarity and PRP maturity matter more than size.
26–100 employees	Moderate	HACCP complexity becomes the major driver.
101–250 employees	Middle-high	Multiple processes or shifts increase time.
250+ employees	High	High-risk food categories can significantly extend duration.

Risk level plays a major role. A small smoked-seafood facility may require more man-days than a medium-sized dry-goods warehouse.

This table isn’t meant to replace official accreditation rules, but it helps you spot quotes that seem unusually high—or suspiciously low.

How Multi-Site ISO 22000 Certification Changes the Man-Day Calculation (Sampling, Central Function, Remote Audits)

Multi-site certifications follow a different logic because certification bodies must evaluate both the central function and a sample of operational sites.

Here’s how it typically works:

• Central Function Audit: Always required.
• Site Sampling: The number of locations audited depends on sampling rules, not the total number of sites.
• Site Variability: More diverse sites mean more samples.
• Remote Audits: Some activities can be done remotely, reducing on-site time.

Common Mistake: Assuming every site requires the same number of man-days. Sampling rules usually reduce the total—if your sites share the same processes and controls.

The more standardized your system, the more efficient your audit duration becomes.

ISO 22000 Audit-Duration Man-Day Calculator (Step-by-Step Framework)

Here’s a simple calculator you can apply immediately:

1. Identify your employee count range.
   This sets your baseline man-days.
2. Determine HACCP complexity.
   High-risk foods mean more audit depth.
3. Clarify your product categories.
   Too many categories inflate man-days unnecessarily.
4. Define your scope accurately.
   Avoid vague or overly broad descriptions.
5. Apply multi-site rules (if relevant).
   Central function + sampling.
6. Identify add-ons:
   • Additional shifts
   • Seasonal production
   • External warehouses
   • Outsourced processes
7. Check for remote-audit opportunities.
   Some document reviews and interviews may not require on-site time.

This approach helps you predict audit duration before requesting quotes, and it positions you to challenge excessive or unclear man-day allocations.

How to Reduce ISO 22000 Man-Days Without Affecting Audit Quality

Man-days shouldn’t be reduced by cutting corners. They can be reduced by strengthening your system.

Here’s what truly works:

• Consolidate similar product categories.
• Remove outdated processes from your declared scope.
• Improve document organization; auditors spend less time searching.
• Strengthen your internal audit to catch gaps early.
• Use remote readiness checks where allowed.
• Align PRPs tightly with Codex and ISO/TS 22002 requirements.

A client once reduced their man-day requirement just by restructuring their HACCP plan—grouping hazards logically, improving flow diagrams, and removing outdated steps. The certification body reviewed the new documentation and adjusted their estimate.

Common Mistake: Trying to “hide” complexity to reduce man-days. Auditors always uncover reality during Stage 2, which often leads to more time added—not less.

FAQs: ISO 22000 Man-Day Calculation & Audit Duration

Why do certification bodies give different man-day estimates?

Because each interprets complexity and risk differently. The rules are standard, but the judgment isn’t.

Can we negotiate man-days?

Yes, especially if your scope is well-defined or if you qualify for multi-site sampling.

Does a larger workforce always mean more man-days?

Not always. High-risk processes can outweigh headcount in certain cases.

Conclusion: Your Clear Path to Accurate ISO 22000 Audit-Duration Planning

Once you understand how man-days are calculated, planning becomes much simpler. Your audit duration depends on a mix of size, scope, complexity, and risk—not guesswork. When you structure your Food Safety Management System with clarity, you reduce uncertainty, avoid inflated audit durations, and create a smoother path to certification.

I’ve helped many organizations refine their scope and man-day estimates, and the results are always the same: less stress, fewer surprises, and more predictable costs.

If you want a personalized man-day estimate or need help preparing your documentation before requesting quotes, I’m here to help you map out the best approach.