Following up to Francesco:
From what I have heard from my interviews (and have experienced myself), it is very hard to make more money in the long run as a Freelancer if you come from a consulting firm that pays decently.
Of course, if you look at junior salaries that may work, but don't forget that in a consulting firm you have a career progression with corresponding higher incomes. You will have a very hard time making a Partner or even Senior Manager salary as a Freelancer because you don't have the pyramid working for you.
Many freelancers also underestimate the costs of all the benefits their company pays - health insurance, retirement savings, company car, training, ... Once all of that comes out of your own pocket, you'd be surprised how much you have to earn to beat a Consultant package of salary and benefits.
That may work in a very good year, where you can book 200 billable days at a good daily rate - but it would be foolish to assume that every year is like that. If you manage to bill a 100-120 days a year on average, you're much closer to reality for most freelancers.
Your daily rate also usually maxes out at some point, I know very few freelancers that have daily rates exceeding 1,500€ (in Germany) AND who are still booked on longer-term projects, where you can bill 50, 80 or 100 days. And those I know have 10+ years of experience.
So do the math (Example for Germany):
- Even if you manage to consistently charge 1.500€/day (and that's VERY good), you bill 120 days, you earn 180k.
- Deduct all non-chargeable costs of doing business (office, IT, insurance, travel, ...) and "benefits" - make that 50k
- You end up with 130k a year - that's a Senior Con salary in the firm where I used to work. Not even with a great bonus. And then the Senior Con becomes Manager after two years, jumping to 160k, and then to Senior Manager (>200k) - while you have maybe managed to add 100€ to your daily rate...
Of course, I've read all the books like "Million Dollar Consulting" and "Book yourself solid" - but the reality is, that very, very few freelancers manage to get to that level.
PS: I'm also not sure if you can start a consulting business on weekends. Of course, you can do some of the preparations (admin, website etc...), but if you work with corporate clients, those tend to want to work with you during normal business hours...