Based on your financial expertise, provide your response or viewpoint on the given financial question or topic. The response format is open.

Calculate Estimated Tax on Hobby Business LLC
I assume your employer does standard withholding?  Then what you need to do is figure what bracket that puts you in after you've done all your normal deductions.  Let's say it's 25%.  Then multiply your freelance income after business expenses, and that's your estimated tax, approximately.  (Unless the income causes you to jump a bracket.) To that you have to add approximately 12-13% Social Security/Medicare for income between the $90K and $118,500.  Filling out Form 1040SSE will give you a better estimate. But there is a "safe harbor" provision, in that if what you pay in estimated tax (and withholding) this year is at least as much as you owed last year, there's no penalty.  I've always done mine this way, dividing last year's tax by 4, since my income is quite variable, and I've never been able to make sense of the worksheets on the 1040-ES.