Posted By Ciaran McAleenan John, HSE calculates the incidence rates per 100,000 employees while others prefer to calculate frequency rates per million hours worked. Either way is fine providing consistency is applied to allow you to compare from year to year or to compare with similar companies in your industry. You need to work with figures that are less prone to distortion. That is work with the reportables since they are legally defined. Calculations are as follows; Injury Incidence rates Divide the number of reportable injuries in the period by the numbers employed in the same period and then multiply by 100,000 Injury Frequency rate Divide the number of reportable injuries in the period by the total number of hours worked in the same period and then multiply by 1,000,000 Some smaller companies may use a lower comparator such as per 1000 employees. Regards Ciaran mailto:ciaran@confinedspaces.com