A VERY general rule is that you need to double the hourly take-home pay you would receive as an employee in the same role, though to an extent this depends on circumstances.
You need to consider
- different tax treatment (see )
- cost of home office, possibly internet, phone, heating, electricity
- cost of transport
- insurance
- provision for holidays, potential sick-days etc.
So if your take-home pay was, say, 16/hour you should aim at 32/hour in your negotiations.
To help argue your case, make a list of all that was provided for you in your job (e.g. workspace, computer, BIK, etc.) and work out the employer PRSI contribution that would have been paid for you.
HTH