>Front-end contracting is typically full-time contracts on-location for between 6 and 12 months. It typically pays 100+ USD an hour, meaning a monthly income of 16K USD or so given a standard 40 hour workweek.
A lot of those 16K will go away in taxes and social costs though. I am not sure what most freelancers use for estimates but somewhere between 50-75% should probably be deducted before getting a comparable number to a salary.