Free calculator
The RR446 fatigue and risk index, in your browser.
The HSE withdrew its Excel tool in June 2021 and never replaced it. The method is still published and widely used. Score a shift against it here. No signup, no spreadsheet, no macros warning.
An independent implementation of the method published in HSE Research Report RR446 (2006). Not an HSE product and not endorsed by HSE.
One shift is a taster. The rota is the hazard.
Drop the CSV or XLSX your rota tool exports. Every shift is scored in the browser session; nothing is saved until you ask.
Deterministic scoring against HSE RR446. Nothing is stored unless you choose to save. The same engine scores whole rotas in RotaPulse, free up to 10 workers.
Sector versions
The same engine, opened on the profile your sector works to, with worked examples in its own words.
- Rail fatigue calculator for NR/L2/OHS/003
Opens on the Network Rail profile: the day and night fatigue index triggers, the risk index trigger, and the hard limits on duty length and rest.
- Junior doctor and ward rota fatigue calculator
Scores a ward night run or an on-call sequence on the general profile, with the junior doctor contract limits set out alongside.
How to read the two numbers
The Fatigue Index is a probability, expressed as a percentage, that a person working this pattern will feel very fatigued at some point during the shift. An FI of 20 means roughly one person in five on this pattern is likely to hit high sleepiness. The Relative Risk is comparative: 1.4x means an estimated 40 percent more fatigue-related incident risk than the reference pattern of 12-hour shifts on a two-day, two-night, four-off cycle.
There is no pass mark. The thresholds circulating in the rail industry were indicative, built to flag patterns for attention. A pattern scoring just under a threshold is not safe, and one scoring just over is not banned. The number starts the conversation about the pattern, the task, and the person. It does not end it.
What this calculator cannot see
It scores the shift you type in, as planned. It knows nothing about the overtime swap agreed by text on Sunday night, the two-hour commute, the second job, or whether anyone actually slept. Every published evaluation of the FRI makes the same point: planned rotas understate real fatigue. It also models a statistical average person, so using a score to judge an individual, in either direction, is a misuse.
We built on the FRI anyway, because in most UK shift operations the alternative is not a better model. It is nothing. A transparent, published, imperfect model applied to every rota beats a perfect model applied to none. The full account is on the methodology page.
Questions
What is the HSE Fatigue and Risk Index?
A method published in HSE Research Report RR446 (2006) for scoring shift patterns. It produces two numbers: a fatigue index, the estimated probability that someone working the pattern will feel very fatigued during the shift, and a risk index, the relative risk of a fatigue-related error compared with a reference pattern. ORR's guidance discusses it alongside its limitations, and Network Rail's NR/L2/OHS/003 sets action thresholds against it.
What happened to the official HSE Excel calculator?
The HSE withdrew the FRI spreadsheet from its website in June 2021. The version of Excel it ran on could no longer be supported, and the HSE said the tool's design needed improvement to promote better understanding of its outputs and limitations. The methodology remains valid and published; the official tool was never replaced.
Is this calculator really free?
Yes. Scoring a shift on this page needs no account and no card. RotaPulse the product, which scores whole rotas and produces audit-ready PDF reports, has a free tier up to 10 workers and published prices after that.
Is a score below the threshold a pass?
No. There is no pass mark. The thresholds used in the rail industry were explicitly indicative, meant to flag patterns for attention. The ORR has documented cases of the FRI being misused to justify work patterns that clearly needed further action. Treat a score as the start of a conversation, not a verdict.
What can the FRI not see?
It scores the pattern you type in, not the shift as actually worked. It models a statistical average person, not an individual: no commute, second job, health, or real sleep data. Planned rotas systematically understate real fatigue exposure, so re-scoring worked hours matters as much as scoring the plan.
Which compliance profiles does it support?
Standard UK Working Time Regulations, Network Rail NR/L2/OHS/003, and the HGV Road Transport Working Time Directive. The profile sets the regulatory warning thresholds; the FI score itself is the same published methodology in every profile.
Is there a version for rail or for healthcare?
Yes. The rail calculator opens on the Network Rail NR/L2/OHS/003 profile and explains its triggers and hard limits. The healthcare calculator scores ward and junior doctor shifts on the general Working Time Regulations profile, because no healthcare body has published a sector standard for the index. Both use this same engine.
Every shift on the rota, scored the same way.
RotaPulse scores every shift on a rota, flags the risky patterns in plain English, suggests the smallest fix, and produces an audit-ready PDF. Free up to 10 workers, published prices after that.
Sources: HSE Research Report RR446 (Spencer, Robertson and Folkard, 2006); ORR, Managing Rail Staff Fatigue, Appendix D. RotaPulse is a TeZe Ltd product. This page is guidance, not a safety certification.