The math freelancers skip
A 40-hour week isn't 40 billable hours. Sales calls, invoicing, learning, admin — realistically 60–80% utilization at best. Then add ~25% for software, insurance, retirement and taxes. A $100K target with those numbers demands ~$108/hour, not the $50 most freelancers charge. Price from your life, not from fear.
Arithmetic based on your inputs — adjust until it stings a little.