If your employer rents you out to a customer the general guideline is that they have to charge double your rate to make money.
If you make $83K a year you see on your paycheck that your employer is paying you about $39.90 per hour (83K/2080) but you don't really work 2080 hours per year. You have holidays, vacation, sick...
Of course the employer covers your benefits, and their portion of social security, and state unemployment insurance.
Plus overhead for admin, billing, payroll, electricity, rent, equipment...
In the end they have to pay for all of this and spread it over your billable hours (2080-vacation - sick - holidays). Which some will guesstimate as pay the employee $83K, charge the customer $83 per hour.
Now do you need to charge that much. No. You don't have all the overhead, But you still have the reduced hours, and the need to pay benefits. Though if you have insurance from another source, then you may not need to to charge for that.
I have been looking for a W2 position at about $83K, or W2 hourly of
$45 to $50.
That might be a little low. 83K divided by 1880 (2080 - 5 weeks) is $44.15 an hour. That doesn't give you much room for benefits and required expenses.
Note: W2 contractor is not a correct term. If you are W2 you are an employee. If you are a independent contractor you will get a 1099.