Freelance income isn't taxed like a paycheck — nobody withholds anything for you. This estimates the Social Security and Medicare portion (the "SE tax") you owe on top of regular income tax, so you know what to set aside.
Your inputs
Net self-employment income (yearly)$60,000
Revenue minus business expenses — the profit your Schedule C actually shows.
Taxable SE earnings (92.35%)$55,410
Social Security portion (12.4%)$6,871
Medicare portion (2.9%)$1,607
Estimated self-employment tax (yearly)
$8,478
14.1% of net income
Set aside per quarter
$2,120
Set aside per month
$707
This covers SE tax only (Social Security + Medicare) — it doesn't include federal or state income tax on top. Social Security applies up to the annual wage base (estimated here at $176,100); Medicare applies to all net earnings with no cap. Check the current IRS figures before filing.