Stop guessing your quarterly estimated tax — $12 spreadsheet

The IRS 1040-ES periods aren't real quarters (Q1 is 3 months, Q4 is 2), self-employment tax has two brackets most people miss, and getting it wrong means an underpayment penalty even if you pay in full by April. This spreadsheet does the math for you and shows the 4 actual due dates.

What's inside

Format: .xlsx, opens in Excel, Google Sheets or LibreOffice. Educational estimate tool, not tax, legal or financial advice — verify final figures with a CPA or the IRS.

How it works

  1. Pay $12 below. No account, no signup.
  2. You get an instant download link on the confirmation page: the .xlsx file, ready to edit.
  3. Open it, fill in the input cells (net SE income, other income, prior-year tax if you have it), and your 4 quarterly payments appear.

$12 one-time

Get the spreadsheet — $12

Who this is for

US-based freelancers, 1099 contractors and solo consultants who file a Schedule C and pay quarterly estimated tax. Built for single filers; if your situation is more complex (multiple income types, married filing jointly, state estimated tax), use this as a starting point and confirm with a CPA.