Lost Working Days Calculator

Calculate working days lost over a selected period and estimate the proportion of working time lost.

Enter the period and working pattern

Start date of the period.
End date of the period.
Used to estimate working days in the period.
Enter working days lost to absence or another specified reason.

Result

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Enter the information and select Calculate.
How the calculation works
Complete the relevant fields to see the calculation and an explanation of the result.

Practical use

Lost working days can be useful when reviewing absence, operational disruption or other periods where working time was unavailable.

Important: If you are measuring sickness absence, use the employee's actual working pattern where possible rather than applying a generic five-day week.

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This calculator provides general HR information and practical use. It does not constitute legal advice. Check current official guidance and the employee's contract, policy and applicable legislation before relying on the result.