Average score for a question = sum of all answers to it ÷ number of answers
eNPS = % of promoters − % of detractors (both as a share of everyone who answered)
ESI = (average of the three questions − 1) ÷ 9 × 100
Participation rate = people who answered ÷ people who received the survey × 100
Absence rate = days (or hours) absent ÷ scheduled working days (or hours) in the period × 100
Turnover rate = people who left ÷ average headcount × 100
Annualized = turnover for the period × (12 ÷ number of months)