A rough read on what to set aside, so the payment due date doesn't surprise you.
A common rule of thumb for the self-employed is to set aside about 30% of net income for federal and self-employment tax combined, then split that into four quarterly payments. On $120,000 of net income, that's roughly $36,000 set aside for the year — $9,000 per quarter.
The actual rate depends on total income, filing status, and state taxes — this is a starting estimate for setting cash aside, not a number to file with.
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