As a freelancer, nobody covers your paid vacation, sick days, or the employer half of payroll taxes — your hourly rate has to build all of that in yourself, which is why it looks so much higher than an equivalent salaried wage. Tax rules vary by country; enter your own effective rate (income tax plus self-employment tax combined) rather than relying on a default here.
Your Target Income
$
$
Software, equipment, insurance, office space, etc.
Tax
Self-employment tax typically covers both the employee AND employer share of Social Security/Medicare (or your country's equivalent) — an employer normally pays half of this for you.
Your Working Time
Vacation, sick days, holidays combined.
Hours actually billed to clients — the rest goes to admin, marketing, invoicing.