Before you can make a profit, you have to cover your bills. Here’s how many hours that takes.
Revenue needed = personal costs ÷ (1 − tax rate) + business costs. Break-even hours = revenue needed ÷ hourly rate. Personal costs are grossed up for tax because you pay them from after-tax money.
If your break-even uses most of your available hours, there's no room for slow months, holidays or illness. Raise your rate or lower your costs until there's a comfortable margin.
Software, equipment, insurance, accounting, marketing, workspace and anything else you pay to run the business. Business costs are often tax-deductible, so they aren't grossed up for tax here.
The hourly rate calculator starts from your income goal and gives you a rate. This one starts from your rate and tells you the minimum work you need to survive.