Frequently Asked Questions
Who needs to pay estimated quarterly taxes?
If you expect to owe $1,000 or more in taxes for the year and your income is not subject to withholding (or your withholding is insufficient), you likely need to pay estimated taxes. This applies to freelancers, independent contractors, sole proprietors, partners, and S-corp shareholders.
When are quarterly estimated tax payments due?
For the 2025 tax year, estimated tax payments are due on April 15, June 16, September 15, and January 15 of the following year. If a due date falls on a weekend or holiday, the deadline moves to the next business day.
What is self-employment tax and how is it calculated?
Self-employment tax is the Social Security and Medicare tax that self-employed people pay. The rate is 15.3% (12.4% for Social Security and 2.9% for Medicare) on 92.35% of your net self-employment earnings. Social Security tax is capped at $176,100 in wages for 2025.
What is the safe harbor rule for estimated taxes?
The safe harbor rule protects you from underpayment penalties if you pay at least 90% of your current year tax liability OR 100% of your prior year tax liability (110% if your AGI exceeded $150,000). Meeting either threshold means no penalty.
What happens if I underpay my estimated taxes?
The IRS charges an underpayment penalty based on the federal short-term interest rate plus 3 percentage points, currently around 8% annualized. The penalty is calculated per quarter, so paying late for one quarter only affects that quarter.
Do I need to pay state estimated taxes too?
It depends on your state. Nine states have no income tax: Alaska, Florida, Nevada, New Hampshire, South Dakota, Tennessee, Texas, Washington, and Wyoming. All other states require estimated payments.
How does EstiMate calculate my taxes?
EstiMate subtracts business expenses from gross income, calculates self-employment tax, applies your deduction, computes federal and state tax using 2025 bracket rates, then divides the total by four for quarterly payments.
Is my data safe with EstiMate?
Yes. EstiMate runs entirely in your browser. No financial data is ever sent to our servers or stored anywhere. All calculations happen on your device. There is no account creation or email collection.
What is the difference between standard and itemized deductions?
The standard deduction is a fixed amount based on filing status ($15,000 for Single in 2025). Itemized deductions total your specific deductible expenses like mortgage interest and charitable donations. Choose whichever is higher.
Can S-Corp owners use this calculator?
Yes, with some caveats. S-Corp owners who pay themselves a reasonable salary have FICA taxes withheld from wages. This calculator applies to pass-through income beyond the salary. For complex S-Corp situations, consult a tax professional.
Still have questions? Try the calculator or consult a qualified tax professional.