The HSE retired its fatigue calculator five years ago. I put one back.
In June 2021 the HSE quietly removed the Fatigue and Risk Index calculator from its website. Not because the methodology was wrong. The spreadsheet ran on a version of Excel that could no longer be supported, and the HSE said the tool's design needed improvement so people would better understand its outputs and its limitations.
Then nothing replaced it.
Five years on, the FRI is still the UK's reference method for scoring shift patterns. It is what Network Rail expects under NR/L2/OHS/003. It is the tool the ORR's fatigue guidance discusses at length. It is the method a research team used to score 95 junior doctor rotas in a published study. And the official way to run it is a retired spreadsheet that circulates on safety resource sites like a relic, complete with macro security warnings.
That gap always struck me as absurd. A published, free, peer-evaluated safety methodology that most of the people who need it cannot practically run.
So I built a browser version. It is at rotapulse.co.uk/fri-calculator, it is free, and there is no signup. You enter a shift, pick a compliance profile (standard WTR, Network Rail NR 003, or HGV Road Transport WTD), and the deterministic engine returns the Fatigue Index, the Relative Risk, the component breakdown, and plain-English warnings. Nothing you enter is stored.
What it is
The scoring is the published RR446 methodology: cumulative load, shift timing against the circadian low, job demand, rest gaps, travel time deducted from effective rest. The same engine scores whole rotas in RotaPulse; the calculator is that engine pointed at a single shift.
Deterministic matters here. The same inputs return the same score, every time, and every score carries its engine version. No AI anywhere near the numbers. If you and your regulator run the same shift, you get the same answer.
What it is not
The FRI scores the pattern you type in. It does not know whether anyone slept, what the commute was, or what actually got worked after the plan was published. It models a statistical average person, not your colleague on their fourth night. And there is no pass mark: the thresholds the rail industry uses were always indicative, built to flag patterns for attention, and the ORR has documented cases of the tool being misused to justify rosters that clearly needed fixing.
I wrote a longer, more uncomfortable piece about those limitations here. The short version: use the score to compare patterns and start conversations. Never use it to end one.
Why free
Partly because the thing it replaces was free, and putting a paywall in front of a withdrawn public safety tool felt wrong. Partly because the people I most want using it, the rota coordinator at a care home, the transport manager with six trucks, the rail subcontractor priced out of enterprise fatigue software, are exactly the people who will not sit through a sales call to check one shift.
If one shift turns into a whole rota, RotaPulse scores those too, free up to 10 workers, published prices after that. But the calculator asks nothing of you. Score a shift, read the warnings, argue with the number. That is what it is for.
The calculator is at rotapulse.co.uk/fri-calculator. No signup, no spreadsheet, no macros warning.