If you hire someone full time, you can do the math that way.
But the market rate for a freelance midlevel US-based engineer would be about double per hour what you'd pay a full-time employee of the same level, to account for taxes/PTO/health care/etc.
Would be happy to find something at half that, but there’s no work right now. Lots of ghost jobs and even upwork has twenty+ applicants fighting over $30/hr scraps.
But the market rate for a freelance midlevel US-based engineer would be about double per hour what you'd pay a full-time employee of the same level, to account for taxes/PTO/health care/etc.