Quarterly Estimated Tax Calculator
For freelancers and self-employed: estimate the quarterly tax payment due to avoid IRS underpayment penalties.
Inputs
About Quarterly Estimated Tax Calculator
Safe harbor rule
Avoid penalties by paying the lower of: (1) 90% of this year's federal tax, or (2) 100% of last year's federal tax — 110% if last year's AGI was over $150,000. Fill in Last year's total federal tax and Last year's AGI and the calculator shows both targets, marks the one that is your safe harbor, and divides it by four. Tax already withheld counts toward the target, so it is netted off the per-quarter figure.
Due dates
Q1: April 15. Q2: June 15. Q3: September 15. Q4: January 15 of next year. Late payments accrue interest plus a small penalty even if you ultimately get a refund.
SE tax
Self-employment tax is 15.3% of 92.35% of your net business profit: 12.4% Social Security on earnings up to the annual wage base ($176,100 for 2025) and 2.9% Medicare with no cap. Past the wage base only the Medicare half keeps accruing, so your effective SE rate drops — this calculator applies that cap. Half of the SE tax is deductible against your AGI.
Does filing status matter?
Yes. Filing status sets both your standard deduction and your federal bracket thresholds, so the calculator asks for it instead of assuming single. Federal brackets run the full 10% to 37%.
What about state estimated payments?
The state figure here is a flat rate you enter, applied to your federal taxable income as a rough guide. The safe harbor shown is the federal rule only — most states run their own estimated-payment schedule and their own penalty test.