This is NOT a duplicate of: Calculate hourly wage from annual salary offer? - that's about whether the employment salary is calculated hourly/daily/annually/whatever.
Currently I do a task for a company as an external contractor. I turn up, do the task for X hours, and leave, and then invoice them for X hours of my time at the hourly rate that we initially agreed.
They're now looking to employ someone (possibly me) to do that same job permanently, as an employee (so, salary, pension, sick leave, etc.)
What things should I be thinking about when comparing the rates?
Obviously there's pension contributions & Sick Leave, as noted above, but are there any other things I should be accounting for in judging how the rates compare?