How long does it take to become a mechanical engineer?

You need a four year BS degree at major universities and a good interview during this or following. Working as a paid or unpaid intern while in college can make the job hunting easier.

After you receive your degree, some states require you to work with a professional engineer for a period of time before you are allowed to take your state's PE exam. For example: In California you must work under a PE for 2 years before being allowed to take the PE exam, but in Nevada it's 4 years.