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First Aider Requirement Calculator

Work out first aider requirement instantly with clear inputs, formula shown and shareable results.

About First Aider Requirement Calculator

First aid provision is set by a ratio that tightens with workplace hazard: roughly one first aider per hundred workers in a low hazard office, one per twenty-five in high hazard work. Cover must exist on every shift, and an allowance for annual leave, training and sickness is needed so the ratio holds in practice rather than only on paper.

Formula

First aider count

Per shift = ceil(workers per shift / ratio); total = per shift x shifts x (1 + absence allowance)

Worked example

With the default values below, First Aider Requirement Calculator returns Trained first aiders required of 8. Change any input above and every figure here is recalculated in your browser.

Inputs used

Workers on siteminimum 1
250
Workplace risk levelone of Low hazard — one per 100 workers, Medium hazard — one per 50 workers, High hazard — one per 25 workers
Medium hazard — one per 50 workers
Shifts per dayminimum 1
2
Allowance for leave and absenceaccepts 0–100 %
25 %

Results

Trained first aiders required
8
First aiders needed per shift
3
Workers per first aider
50
Requirement before absence cover
6

Step by step

  1. 1Values used
  2. 2First aider count
  3. 3Trained first aiders required= 8
  4. 4First aiders needed per shift= 3
  5. 5Workers per first aider= 50
  6. 6Requirement before absence cover= 6

Assumptions and limits

  • The result is derived only from the 4 inputs listed above. Anything not among them is not part of the calculation.
  • In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
  • Figures are rounded for display to whole numbers, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.
  • Preliminary estimate only. First aid provision must be determined by a documented needs assessment under the applicable first aid regulations.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

Preliminary estimate only. First aid provision must be determined by a documented needs assessment under the applicable first aid regulations.

Frequently Asked Questions

How is the First Aider Requirement figure worked out?

Per shift = ceil(workers per shift / ratio); total = per shift x shifts x (1 + absence allowance). First aid provision is set by a ratio that tightens with workplace hazard: roughly one first aider per hundred workers in a low hazard office, one per twenty-five in high hazard work.

Is the ratio a legal minimum?

Most regulators publish it as guidance rather than a fixed rule, expecting a needs assessment that also considers remoteness, shift patterns, hazard type and travel time to hospital.

What values do I need to enter?

This calculator takes 4 inputs: Workers on site, Workplace risk level, Shifts per day, Allowance for leave and absence. The pre-filled defaults are a realistic worked example — replace them with your own site or project figures.

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