Audit Days Calculator

Estimate certification audit time for ISO 9001, ISO 14001, ISO 45001, integrated systems, ISO 22000, FSSC 22000 V7 and BRCGS Food Safety Issue 9.

Estimate how many auditor-days a certification audit needs for ISO 9001, ISO 14001, ISO 45001, an integrated management system, ISO 22000, FSSC 22000 Version 7 or the BRCGS Global Standard for Food Safety Issue 9. The calculator applies the accreditation and scheme rules that certification bodies must follow, so you can plan your budget and compare proposals.

Why audit time is regulated

Accredited certification bodies cannot choose audit time freely. The International Accreditation Forum (IAF) sets mandatory rules for management system audits, ISO 22003-1 sets them for food safety management systems, and scheme owners such as FSSC and BRCGS add their own. A proposal that offers far fewer days than these rules allow should be questioned: either the certification body is not accredited for the scope, or the audit will not be credible.

ISO 9001, ISO 14001 and ISO 45001: IAF MD 5

Effective number of personnel is the starting point: permanent, temporary and part-time staff on all shifts, plus contractors within the scope. Part-time staff are converted to full-time equivalents (for example, 30 people working 4 hours a day count as 15).
Tables QMS 1, EMS 1 and OH&SMS 1 give the initial audit time (Stage 1 + Stage 2) for each personnel band. ISO 9001 has one column; ISO 14001 and ISO 45001 depend on the complexity of the activity (high, medium, low, and limited for ISO 14001).
Complexity follows the sector lists in IAF MD 5. For example, chemicals, oil and gas, mining and construction are high for both environment and OH&S; food manufacturing is medium; offices and business services are limited for the environment and low for OH&S.
Adjustments: factors such as several buildings, high regulation, many languages or high-risk activities increase the time; a very small site, a mature system, prior knowledge of the client or a high level of automation can reduce it. The total reduction must not exceed 30% of the table value, and every adjustment must be justified.
Surveillance audits take about one-third of the initial time each year, and recertification about two-thirds; neither is normally less than one day. At least 80% of the calculated time should be spent on site, and time is rounded to the nearest half day.

Integrated management systems: IAF MD 11

When ISO 9001, ISO 14001 and ISO 45001 are audited together, the certification body first calculates the time for each standard, adds them, and then reduces the total according to how far the system is really integrated: shared documentation, one internal audit programme, one management review, combined objectives and processes. The calculator offers no reduction, 10% or 20%; the certification body assesses the actual level.

ISO 22000: ISO 22003-1:2022

For food safety management systems the minimum audit time for one site is Ds = TD + TH + TFTE, where TD is the basic time for the food chain category, TH is the time for each additional HACCP study, and TFTE depends on the number of full-time equivalent employees. The calculator uses the Annex B values as published by an accredited certification body; always confirm them against your licensed copy of the standard. Surveillance takes one-third and recertification two-thirds of the initial time, with a minimum of one day (half a day for farming categories A and B).

FSSC 22000 Version 7

The audit time is Ds (from ISO 22003-1) plus TFSSC for the FSSC additional requirements: 0.5 day below 100 FTE with up to 2 HACCP studies, 1 day from 100 to below 250 FTE with up to 2 studies, and 1.5 days for 250 FTE or more, or 3 or more studies.
No reductions to Ds or TFSSC are allowed. The minimum Ds is 1 day, and categories C, D and K never go below 2 days. Sites with fewer than 20 FTE and up to 2 HACCP studies, and subcategory FII, may go down to 1.5 days.
Surveillance is one-third of Ds plus TFSSC, and recertification two-thirds of Ds plus TFSSC. Days are rounded up to the next quarter day.
At least 0.25 day for preparation and 1 day for reporting (0.5 day for a 1.5-day audit) are added. At least one surveillance audit in each cycle is unannounced. Upgrade audits to Version 7 take place from 1 May 2027 to 30 April 2028.

BRCGS Global Standard for Food Safety Issue 9

BRCGS audits are annual, so the calculator gives the time for each audit, in hours and in 8-hour days.
The base table uses the employees on the main shift (including seasonal staff) and the size of the manufacturing facility including on-site storage, for 1 to 3 HACCP plans: from 18 hours for small sites up to 34 hours for large ones.
Time is added for more HACCP plans (4 hours for 4–6 plans, 8 hours for 7 or more), 2 hours for each high-risk, high-care or ambient high-care area, 1 hour for traded products, and for voluntary modules.
Very small, simple sites may be audited in 12 hours, but no audit is shorter than 8 hours. Other factors may not change the time by more than 30%. About half of the audit is spent in production, and never less than 30%.

Multi-site organisations

Tick the multi-site option in any tab. Each standard has its own rules, because the risk of auditing only a sample of sites is not the same for every activity:

ISO 9001, ISO 14001, ISO 45001 and integrated systems (Global ACI-TECH-3-001, formerly IAF MD 1): sampling is allowed when one management system is run by a central function with authority over all sites, with a central management review, internal audits of every site and very similar processes at each site. The sample is √x sites at the initial audit, 0.6√x at each surveillance and √x (or 0.8√x when the system has proved effective) at recertification, rounded up, with at least a quarter chosen at random. The central function is audited every time. Each sampled site may have up to 50% less time. Without sampling, all sites are audited at initial and recertification audits and 30% of them each year.
ISO 22000 (ISO 22003-1:2022, clause 9.1.5): sampling is allowed only for farming (A and B: √x sites), for re-heating or limited-preparation catering outlets (E), retail and trading (F) and storage and distribution (G): all sites up to 20, then 20 + √(x − 20). Every site in other categories, such as food manufacturing, is audited.
FSSC 22000 Version 7 (Part 3, 5.3): only BIII, E, FI, FII and G. Up to 20 sites, all are audited; above 20, 20 + √(x − 20). The central function gets its full Ds (at least 1 day), and each site 50% of its Ds plus TFSSC (at least 1.5 days). Every site is audited within each cycle, the whole audit is unannounced once every 3 years, and one group certificate is issued.
BRCGS Food Safety: no sampling. Each site is audited every year and receives its own certificate; a separate head office audit may save about 2 hours per site.

Since 1 January 2026 the IAF mandatory documents are maintained by the Global Accreditation Cooperation (Global ACI). Global ACI-TECH-3-001 replaced IAF MD 1 without substantive change; the audit time tables of IAF MD 5 used above remain the reference until your certification body confirms the Global ACI equivalent.

Frequently asked questions

Is the result a quotation?

No. It is the minimum audit time the rules require for the information you enter. The certification body confirms the scope, the number of sites and the justified adjustments, then sets the final time and fee.

Can a multi-site organisation be audited on a sample?

Only when the conditions above are met and the standard allows it for your activity. Contact us and we will help you prepare the central function, internal audits and records the certification body needs.

Does ITA issue certificates?

No. Certificates are issued by independent accredited certification bodies. ITA helps you prepare: gap analysis, implementation, internal audits and training.

Can remote audits reduce the time?

Remote or blended audits do not reduce the total time. For BRCGS the remote part may not exceed 50% of the audit, and FSSC allows no more than two consecutive full remote audits.

Sources

Planning an audit? Our consultancy team prepares organisations for certification, and our CQI-IRCA Lead Auditor courses explain how certification audits work.

Estimate for planning only. ITA is not affiliated with IAF, ISO, FSSC or BRCGS, and does not issue certificates.