Quarterly Estimated Tax Calculator (IRS Form 1040-ES)

How to do it

1. 1
   Step 1: Open Quarterly Estimated Tax Calculator (IRS Form 1040-ES) and add your input

   Type your numbers or text, add your file, or pick the options you need. Nothing is uploaded: everything stays in your browser.

2. 2
   Step 2: What Quarterly Estimated Tax Calculator (IRS Form 1040-ES) does

   Work out your quarterly estimated tax on freelance or investment income, with the IRS safe-harbor rules.

3. 3
   Step 3: Read the result and compare

   The result appears at once. Change one value to see how the answer moves, then keep the figure that fits your case.

4. 4
   Step 4: Copy or save it

   Copy the result or download it. For an important decision, confirm it with the official source or an adviser.

About this tool

Enter your expected income for the year, your deductions, credits and tax withheld, and last year's tax. The tool computes income tax and self-employment tax, applies the safe harbor (90% of this year's tax or 100% of last year's, 110% when last year's AGI was over $150,000) and shows the four payments.

How the amount is worked out

Self-employment tax is 15.3% of 92.35% of net profit (12.4% Social Security up to the wage base plus 2.9% Medicare). Half of it is deducted from income. Income tax uses the federal brackets for the year you choose, after the larger of the standard deduction and your itemized deductions.

Safe harbor

You avoid the underpayment penalty if you pay at least 90% of this year's tax or 100% of last year's tax (110% when last year's AGI was above $150,000, or $75,000 if married filing separately). If you expect to owe less than $1,000 after withholding, no estimated payments are needed.

Due dates

Payments are due April 15, June 15, September 15 and January 15 of the next year. A date on a weekend or holiday moves to the next business day. State estimated taxes are not included.

Worked example

Single in 2026 with $90,000 of self-employment profit, no withholding, and $14,000 of tax on last year's return: self-employment tax is $12,717 and income tax $9,571, so the year's tax is $22,288. 90% of that is $20,059, but 100% of last year's tax is only $14,000, so you can pay $14,000, which is $3,500 each quarter, and still be inside the safe harbor.

Tips for best results

Check every box before you rely on a result, because one wrong digit changes the whole answer. Use the exact figures from your payslip, bill, certificate or contract, and keep a note of the date you calculated. Rates, thresholds and rules change from time to time, so for tax, fees and legal matters treat the output as an estimate and confirm with the official source named on this page. You can run as many scenarios as you like; nothing is saved or sent, and refreshing the page clears the boxes.