We have created an online calculation which can help you to determine whether it makes sense to file a tax return.
In the calculation you can mention during which period you were in the Netherlands. This is important since the premiums social security are calculated pro rata.
Please also mention the 2012 taxable salary and the wage tax which was withheld by your employer. You can find this information on the year end statement or the last payslip which you received from your employer.
Be advised that the calculation is purely based on the information you provide. The calculation provides an estimate of the refund. The actual refund will be calculated when the tax return is prepared.