What dayrate should a engineer expect.

When I look at dayrates in this sub and r/BEFreelanceDayrate 99% of the posts I see are about IT positions. I am a student and am just looking to inform myself and get a realistic image of salaries and in this case dayrates. I was wondering what dayrate a engineer (ir.) should expect if they had e.g. 5 years of experience and are somewhat specialized in a certain sector/field. Is this a common route people take? I heard if engineers freelance that it often takes form as a consultancy job is this always true or are there other examples?