Absence rate calculator
Absence rate = days lost to unplanned absence / available working days x 100. Available working days are the number of employees multiplied by the working days in the period. For example, 33 days lost by 50 employees over 22 working days is 33 / 1,100 x 100 = 3.0%.
Sick leave and unauthorised absence in the period. Leave out annual and other approved leave.
Scheduled days, excluding weekends and bank holidays. A typical month has 20 to 22. A Monday to Friday year in 2026 has 253 in England and Wales and 251 in Scotland and Northern Ireland (GOV.UK bank holidays).
- Available workdays
- 1,100
- Days lost per employee in the period
- 0.66
- Same rate over a 253-day year
- 7.6 days per employee
The ONS UK sickness absence rate for 2025 was 2.0% of working hours (ONS). ONS counts hours lost to sickness or injury, so compare it with a rate that counts sickness only.
What the rate measures
Absence rate (%) = days lost to unplanned absence / (number of employees x working days in the period) x 100
The top line is the time you lost. The bottom line is the time you scheduled. The result is the share of scheduled working time lost to absence. If you record absence in hours, use hours on both lines.
A company with 50 employees wants its rate for a month with 22 working days.
- Add up days lost. Sickness absence and unauthorised absence in the month come to 33 days.
- Work out available working days. 50 employees x 22 days = 1,100 days.
- Divide and multiply by 100. 33 / 1,100 x 100 = 3.0%.
Days lost per employee is 33 / 50 = 0.66 days in the month. At the same rate over a 253-day working year, each employee would lose about 7.6 days. The calculator shows both.
What to count
- Count sickness absence, with or without a fit note, and unauthorised absence.
- Leave out holiday and other leave approved in advance, family leave such as maternity leave, bank holidays and days the employee was not scheduled to work.
- Use full-time equivalents if many of your staff work part-time. Otherwise a part-timer adds five available days a week to the bottom line and your rate looks lower than it is.
- Use the same definition every period. A rate that changes definition cannot be compared over time.
One long absence can hide the rest of the picture. Consider reporting the rate with and without long spells. To see how short, frequent absences affect one person, use the Bradford Factor calculator.
Comparing with the ONS figure
The Office for National Statistics (ONS) puts the UK sickness absence rate at 2.0% in 2025 (ONS, sickness absence in the UK labour market; dataset, Table 1). The rate was 2.9% for public sector employees and 1.7% in the private sector (dataset, Table 11).
Before you compare your own rate with it, check three things:
- ONS counts hours, not days. Its rate is the share of working hours lost because of sickness or injury, from the Labour Force Survey, for people in work aged 16 and over across the UK (ONS). A days-based rate is close but not the same.
- ONS counts sickness only. If your days lost include unauthorised absence, your rate will be higher than a sickness-only figure.
- The figures are survey estimates. ONS labels them official statistics in development and advises caution when using them (ONS).
ONS also publishes rates by industry and by size of workforce. Our guide to UK sickness absence rates lists them. Your own rate over 12 to 24 months, by department, is a closer comparison than any national figure. The cost of absence calculator turns days lost into a cost in pounds.
How Appsentia works out absence rate
Appsentia works out the rate from the leave records you upload as a CSV or Excel file from any system: sick days divided by each employee's possible working days, using your company's working week and, for UK companies, the bank holidays GOV.UK publishes for each nation. See what Appsentia does for UK employers.
Frequently asked questions
How do you calculate absence rate?
Divide the working days lost to unplanned absence by the working days available, then multiply by 100. Available working days are the number of employees multiplied by the working days in the period. For example, 33 days lost by 50 employees over 22 working days is 33 / 1,100 x 100 = 3.0%.
What is the average sickness absence rate in the UK?
The ONS puts the UK sickness absence rate at 2.0% of working hours in 2025, from the Labour Force Survey. It was 2.9% in the public sector and 1.7% in the private sector. ONS labels these figures official statistics in development.
Should holiday be included in the absence rate?
No. Holiday is planned and approved in advance, so it is not absence. Count sickness absence and unauthorised absence. Leave out holiday, family leave such as maternity leave, and days the employee was not scheduled to work.
Should I use headcount or FTE?
Use full-time equivalents (FTE) if you have many part-time staff, so that a part-timer's scheduled days are not overstated. If almost everyone works the same full-time week, headcount gives the same answer. Use the same basis every time you compare.
Sources
- ONS, Sickness absence in the UK labour market: 2025, article, released 1 May 2026.
- ONS, Sickness absence in the UK labour market: 2025, Table 1 and Table 11, dataset (sicknessabsence2025.xlsx).
ONS figures checked on 11 November 2026. The worked example uses example figures, not averages.
Work out absence rate from your own leave data
Upload leave records from any system as a CSV or Excel file. Appsentia works out your sickness absence rate using your working week and the bank holidays for each UK nation, and shows the cost of sick days and each employee's Bradford Factor. Free for 30 days for up to 10 employees.