Most new freelancers take an old salary, divide by 2,080 hours and quote that. It underprices you by 40–60%, because a freelancer does not bill 40 hours a week.
Rate = ((take-home goal ÷ (1 − tax rate)) + expenses) × (1 + buffer) ÷ billable hours
Sales, admin, invoicing and revisions are unpaid. 50–65% billable is typical for the first years. Track a month of your time to find your real number.
Plug your own numbers into the free rate calculator. Then price projects as hours × rate × a risk buffer of 20–30%.
General information, not legal or tax advice.