For educational purposes only — not tax, legal, or financial advice. Tax laws change frequently. Consult a qualified CPA, Enrolled Agent, or tax attorney for your specific situation.

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    Form 2210 Underpayment Penalty Calculator (2026)

    Estimate the IRS penalty for underpaying your 2026 estimated tax under §6654. The penalty is interest -- the federal short-term rate plus 3 points (7% for Q1 2026) -- on each quarter's underpayment, running to the April 15, 2027 filing date. Check whether a safe harbour clears you, and see the quarter-by-quarter breakdown.

    Guidance, not advice. This calculator runs the rules as published, it doesn't assess your circumstances. Your actual tax may be affected by factors it doesn't cover (deductions, credits, filing status nuances, state-specific adjustments). Always seek financial or tax advice from a qualified CPA, Enrolled Agent, or tax attorney, or contact the IRS. Read our editorial scope →

    Your tax and payments

    Figures from your 2026 return and your 2025 return.

    $

    Federal income tax + self-employment tax, after credits.

    $

    Enter 0 if you had no prior-year liability.

    $

    Over $150,000 requires 110% (not 100%) of prior-year tax.

    $

    W-2 / 1099 withholding. Deemed paid evenly across the four quarters.

    Estimated payments by quarter

    Amount paid on (or near) each due date. Overpayments carry forward.

    $
    $
    $
    $

    Underpayment rate

    §6654 rate = federal short-term rate + 3 points, set quarterly.

    Q1 2026 = 7%; Q2 2026 = 6%. Use the rate(s) in effect during your underpayment period; 7% is a reasonable single-rate default.

    Estimated penalty

    Interest on each quarter's underpayment to the April 15, 2027 filing date.

    $196

    Required annual payment (safe harbour)

    90% of current-year tax$27,000
    110% of prior-year tax$24,200
    Required annual payment (lower)$24,200
    Required each quarter (÷4)$6,050
    Withholding (deemed ¼ per quarter)$12,000
    Total estimated payments$8,000

    Quarter-by-quarter

    Q1 — April 15, 2026$74
    Required: $6,050Paid: $5,000Underpayment: $1,050365 days to filing
    Q2 — June 15, 2026$61
    Required: $6,050Paid: $5,000Underpayment: $1,050304 days to filing
    Q3 — September 15, 2026$43
    Required: $6,050Paid: $5,000Underpayment: $1,050212 days to filing
    Q4 — January 15, 2027$18
    Required: $6,050Paid: $5,000Underpayment: $1,05090 days to filing
    How to reduce this
    Increasing withholding (which is deemed paid evenly all year, even if done late in the year) is the most powerful lever — it can retroactively cover earlier quarters. The annualized-income method may also cut the penalty if your income was seasonal. Paying the balance sooner shortens the interest period.