Man-days calculator
Convert total person-hours into equivalent person-days using your chosen hours-per-day definition.
Enter your values
Check this tool fits your task
Workload arithmetic only. A person-day is not automatically eight hours, a calendar day or an injury-free day.
Your result
Enter your values, or try the example to see how it works.
Calculation breakdown
What to do next
Method and sources
Equivalent person-days = total person-hours ÷ hours per person-day. This is unit conversion, not a prescribed HSE standard.
How to use this tool
- Check the scope and collect measured or verified input values.
- Enter values using the displayed units, then calculate.
- Read the result, calculation breakdown and next steps together.
Worked example
400 person-hours ÷ 8 hours per person-day = 50 person-days. With a 10-hour definition, the same work equals 40 person-days.
The example button fills illustrative values. Where a scope confirmation is shown, check it yourself before calculating.
Method and references
Equivalent person-days = total person-hours ÷ hours per person-day. This is unit conversion, not a prescribed HSE standard.
Workload arithmetic only. A person-day is not automatically eight hours, a calendar day or an injury-free day.
Common questions
Does 50 person-days mean 50 calendar days?
No. Several people can complete person-days of work in parallel.
Is one person-day always eight hours?
No. State the day-length definition and keep it consistent.
Does this measure injury-free time?
No. It totals workload only; it does not establish whether injuries occurred.
Public beta · Check the method and inputs with a competent reviewer before operational use.
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