ISO 27001

ISO 27001 certification cost calculator

Estimate audit fees, implementation cost, and the 3-year cycle total. Adjust assumptions to match quotes and scope. Not financial advice.

Calculator

Start with a few basics, then refine the model in advanced options.

People in scope (FTE)
Used to estimate audit days based on organization size.
Number of sites
Multi-site sampling uses a square root rule.

Estimated sampled sites: 1

Scope complexity
Low is single-product SaaS. High includes healthcare workflows, regulated data, or heavy vendor reliance.
Readiness
Slide from just starting to audit-ready.
Just startingFoundationsControls liveOperatingAudit-ready
Your internal hourly rate
Blended rate for internal implementation effort.
Advanced options
Certification body day rate
Travel / on-site costs
Application / admin fee
Initial audit days (override)
Optional if you already have a quote.
Consultant support (days)
Consultant day rate
Penetration test budget
ISMS tooling cost (annual)
Internal audit
If external, add days at the certification body day rate.
Estimated Year 1 total
$83,500 to $113,000

Audit fees plus implementation effort, tooling, and optional tests.

External audit fees (Year 1)
$12,250

Initial audit days, admin fee, travel, and optional external internal audit days.

Ongoing annual cost
$26,000 to $35,000

Surveillance audit, tooling, and ongoing internal effort.

3-year total (range)
$142,000 to $192,000

Year 1 plus two surveillance years and recertification audit fees.

What is driving the estimate
  • Modeled initial audit days: 6 (based on 50 FTE and 1 site).
  • Readiness level 3 increases internal effort and rework risk.
  • Complexity set to medium affects audit effort.
  • Consultant days included in implementation cost.
  • Surveillance audit days are modeled at one-third of initial audit days, recertification at two-thirds.
Disclaimer: Planning tool only. Actual certification body quotes and implementation effort can vary materially.

How this calculator works

Audit program
ISO 27001 certification runs on a three-year cycle with initial certification (Stage 1 and Stage 2), surveillance audits during the cycle, and recertification at the end of the term.

Why a range
Audit duration and preparation effort depend on size, risk, complexity, and evidence quality. This tool models those drivers and shows a planning range rather than a single number.

Audit days and sampling
Certification bodies calculate audit days based on headcount, risk, and scope. Multi-site audits often use square root sampling for the number of sites to audit.

Methodology and sources

Summary of the baseline model assumptions and sources. Open to see details and links.

This calculator models a three-year certification cycle with initial certification, surveillance audits, and recertification.

Initial audit days are estimated from headcount and complexity, then scaled by multi-site sampling. Surveillance and recert are modeled as shorter portions of the initial effort.

Implementation cost is modeled separately using internal hours by readiness plus optional consultant, penetration test, and tooling budgets.

ISOQAR ISO 27001 audit process explained (audit mechanics and sampling). ISOQAR audit process

ISMS.online certification cycle context (validity and cycle). ISMS.online certification cycle

OneTrust ISO 27001 cost breakdown example (benchmark totals). OneTrust cost example

Secureframe ISO 27001 cost ranges (additional benchmarks). Secureframe cost guide

Vanta penetration test budget range (optional line item). Vanta cost guide

Schellman surveillance and recertification planning heuristics. Schellman timeline factors

How AI Gap Analysis reduces ISO 27001 cost risk

You cannot control auditor day rates. You can control how much rework you trigger.

  • Clause-by-clause gap list from your existing ISMS
  • Evidence map with page links for audit sampling
  • Missing records flagged before Stage 1 and Stage 2

Get an audit-ready evidence pack from your current docs

Upload your ISMS and policies. Get a gap list and evidence map you can hand to your auditor.

FAQ

What does this include versus certification body quotes?

Quotes generally cover audit fees only. This calculator adds internal effort, optional consultant support, tooling, and testing to estimate all-in cost.

Why is it a range?

Audit days and implementation effort depend on scope, complexity, and evidence readiness, so a planning range is more honest than a single number.

How often do surveillance audits happen?

Surveillance audits occur during the certification cycle and recertification happens at the end of the three-year term.

What drives audit days up the most?

Scope complexity, number of sites, and evidence quality are the biggest drivers.

Does healthcare scope cost more?

Typically yes. Regulated data, vendor sprawl, and multiple sites increase audit effort and preparation time.

Can I reduce certification body fees?

Day rates are mostly fixed. You can reduce total cost by improving evidence readiness and minimizing rework.