Quarterly Estimated Tax Calculator

You generally must pay estimated tax if you expect to owe at least $1,000 in federal tax for the year after subtracting withholding and refundable credits. Common cases: self-employed, freelancers, landlords, large investment income earners, partnership/S-corp owners. Employees with side income should adjust W-4 withholding instead.

You avoid an underpayment penalty if you pay either 90% of the current year tax or 100% of last year's total tax (110% if last year AGI was over $150,000). Most self-employed filers use the prior-year safe harbor - it's a known number paid in 4 equal installments, with no need to forecast current-year income.

Federal estimated tax payments for 2026 are due April 15, June 15, September 15, and January 15 (2027) for Q1-Q4 respectively. State estimated payments often have the same dates but check your state revenue department. Use IRS Direct Pay or EFTPS to pay online.

The IRS charges interest at the short-term applicable federal rate + 3% on quarterly underpayments. In 2026 this is roughly 7-8% annualized, calculated separately for each missed quarter. Form 2210 calculates the penalty; the IRS will compute it automatically if you skip the form, but Form 2210's annualized income method can lower the penalty if income was uneven.