Quarterly estimated taxes

What to send the IRS this quarter, by safe harbour or by annualised income, with the reasoning shown.

Taxes → Estimated.

Two methods, and the calculator runs both:

• Safe harbour — pay 100% of last year's tax (110% if your AGI was over $150,000) and you cannot be penalised for underpayment, whatever this year turns out to be.
• Annualised income — project the year from actual results to date. Better when income is seasonal or well below last year's, because the safe harbour would have you overpay.

It shows both figures and recommends the lower one that still avoids a penalty, with the arithmetic laid out rather than asserted.

What it uses: year-to-date profit from your books, your entity type, your state, and any payments already made. Self-employment tax is included for pass-through entities.

Due dates — 15 April, 15 June, 15 September, 15 January — appear as work items on the Bookkeeping Command Center ahead of time.

This is a calculator, not tax advice. Your accountant knows things your books do not.