Figure out exactly how much to pay each quarter and when. No surprises. No underpayment penalties.
Educational only. Not financial advice. Tax laws change — verify with a CPA.
Q1: April 15, 2025 · Q2: June 16, 2025 · Q3: September 15, 2025 · Q4: January 15, 2026. Missing these deadlines can result in an underpayment penalty even if you pay in full by the annual April deadline.
A common rule is 25–30% of net profit for federal taxes — covering 15.3% SE tax plus federal income tax. Add 5–10% for state taxes if applicable. Use this calculator for a precise estimate based on your actual income and deductions.
The SE tax rate is 15.3%: 12.4% for Social Security (on income up to $176,100 in 2025) and 2.9% for Medicare (no limit). You can deduct half of your SE tax as an above-the-line deduction.
The IRS charges an underpayment penalty (currently ~8% annualized) on any shortfall. Avoid it by paying at least 90% of this year's tax or 100% of last year's tax (110% if last year's AGI exceeded $150,000).
Sources: IRS Estimated Taxes Guide, IRS Schedule SE, IRS Publication 334. Last updated March 2026.