cpa-tax
Quarterly Estimated Tax Calculator (2026) — Self-Employed Federal + SE + State Payments
How much should I pay in quarterly estimated taxes? Self-employed business owners owe quarterly estimated tax payments to the IRS to avoid underpayment penalties — and the math has to combine federal income tax, self-employment tax (15.3%), and state income tax into a single number. This calculator estimates all three for the year using 2026 bracket projections, then divides by 4 for your quarterly payment. Verify with a CPA before filing.
Educational estimate using current-year projections — not tax advice. Verify with a CPA against your full return before filing or acting on this output.
How it works
Methodology
Inputs
- Net self-employment income
- Projected business profit after expenses (Schedule C net income or LLC pass-through profit). For S-corp owners, only the W-2 portion drives SE tax; the distribution is reported separately and is not SE-taxable.
- Filing status
- Single / MFJ / HoH / MFS — drives bracket thresholds, standard deduction, and Additional Medicare Tax thresholds.
- State
- State of residence — drives state income tax rate (or zero for no-income-tax states: TX, FL, TN, WA, NV, SD, WY, AK; NH taxes interest/dividends only).
- Other income
- W-2 wages, interest, dividends, capital gains, rental — required to compute total liability honestly and identify any wages already covering taxes via withholding.
Formula
Self-employment tax = Net SE income × 92.35% × 15.3% • 12.4% Social Security on first $184,500 (2026 SS wage base) • 2.9% Medicare on all SE earnings, no cap • +0.9% Additional Medicare Tax on SE + W-2 earnings above $200K single / $250K MFJ / $125K MFS SE tax deduction = ½ × SE tax (deducted above-the-line from federal income tax base) Adjusted gross income = SE income − ½ SE tax + Other income Federal income tax = (AGI − Standard deduction) × Marginal bracket rate (2026 projections) State income tax = State-specific brackets applied to state-taxable income Quarterly payment = (Federal + SE + State) ÷ 4 Safe-harbor minimum = lesser of (100% prior-year liability, 110% if AGI > $150K) OR (90% of current-year liability)
Assumptions
- Uses 2026 bracket projections (single: 10% to ~$11,925, 12% to ~$48,475, 22% to ~$103,350, 24% to ~$197,300, 32% to ~$250,525, 35% to ~$626,350, 37% above) and 2026 standard deduction (~$15,000 single / ~$30,000 MFJ projected).
- Itemized deductions, §199A QBI deduction, business deductions beyond Schedule C net, credits (CTC, EITC, dependent care), prior-year tax, and withholdings all change the actual liability — this estimator runs the simplified case.
- Quarterly safe harbors: pay 100% of prior-year liability (110% if AGI > $150K) OR 90% of current-year liability to avoid underpayment penalty.
- Q1: April 15 · Q2: June 15 · Q3: September 15 · Q4: January 15 of the following year. Note these are unequal periods.
- State income tax handling is simplified — actual state rates vary, and several states (CA, NY, NJ, OR) have meaningfully progressive brackets.
- Not an offer, not approval, consult a CPA before filing.
Worked examples
Schedule C / single-member LLC owner — no-tax state
- Net SE income
- $95,000
- Filing status
- Single
- State
- Texas (no state income tax)
- Other income
- $0
SE tax ~$13,400. Federal income tax ~$12,400. Total ~$25,800 → quarterly ~$6,450. Set aside ~27% of revenue to avoid an April 15 surprise.
High-tax state freelancer
- Net SE income
- $130,000
- Filing status
- Single
- State
- California (~9.3% marginal)
- Other income
- $0
SE tax ~$18,400. Federal income tax ~$19,800. CA state tax ~$8,700. Total ~$46,900 → quarterly ~$11,725. Set aside ~36% of revenue. Don't forget separate CA Form 540-ES quarterly payments.
MFJ couple — one spouse with SE income, one with W-2
- Net SE income
- $70,000 (one spouse)
- Filing status
- MFJ
- State
- Florida (no state income tax)
- Other income
- $95,000 W-2 (other spouse, taxes withheld)
SE tax ~$9,900 on the SE income. Federal income tax on combined $165K AGI ≈ $26K total, of which ~$15K already withheld from W-2 = ~$11K still owed. Total quarterly need ~$5,225 across federal + SE. State zero. Withholding from W-2 partially covers — recompute if W-2 withholding ratio changes.
Frequently asked
Questions readers ask
Do I have to pay estimated taxes every quarter? +
Generally yes, if you expect to owe $1,000+ in tax for the year and you're not having enough withheld from W-2 wages. The IRS imposes underpayment penalties if you don't meet the safe-harbor thresholds (pay 100% of prior-year liability — 110% if AGI > $150K — or 90% of current-year liability, whichever is less).
What are the 2026 quarterly tax due dates? +
Q1: April 15, 2026 · Q2: June 15, 2026 · Q3: September 15, 2026 · Q4: January 15, 2027. Pay via IRS Direct Pay or the Electronic Federal Tax Payment System (EFTPS). Note the quarters are unequal — Q2 covers only April and May; Q3 covers June through August.
What's the self-employment tax rate? +
15.3% on 92.35% of net SE earnings — 12.4% Social Security (up to the 2026 SS wage base of $184,500) + 2.9% Medicare (no cap, plus 0.9% Additional Medicare Tax above $200K single / $250K MFJ). You can deduct half of your SE tax from your income for federal income tax calculation.
How much should I set aside for taxes as a self-employed owner? +
Common rule of thumb: 25-30% of net business profit. Higher (30-35%) if you're in a high-tax state (California, New York, New Jersey) or in the 24%+ federal bracket. Lower (20-25%) in no-income-tax states (Texas, Florida, Tennessee, Washington, Nevada, South Dakota, Wyoming, Alaska, New Hampshire on interest/div only). Run this calculator for your specific number.
What's the safe harbor for quarterly estimated taxes? +
Two safe harbors avoid underpayment penalties: (1) pay 100% of your prior-year total tax liability — 110% if prior-year AGI was over $150K ($75K MFS); OR (2) pay 90% of your current-year liability. Meet either by April 15 of the following year through a combination of quarterly estimates + withholdings, and the IRS won't penalize you even if you owe more.
What happens if I miss a quarterly payment? +
The IRS calculates an underpayment penalty on Form 2210 — it's effectively interest on the unpaid balance from the missed quarter's due date until paid. The 2026 rate floats with the federal short-term rate + 3% (typically 7-8% annualized in recent years). Catching up on the next quarter doesn't eliminate the prior-quarter penalty; pay the missed amount ASAP via EFTPS to stop the meter.
Do quarterly payments cover state taxes too? +
Federal estimated payments cover federal income tax + SE tax only. State income tax is separate — most states require their own quarterly estimated payments on the same April / June / September / January schedule. Verify your state's rules; some states have different due dates, lower thresholds, or no estimated tax requirement at all (the 9 no-income-tax states).
How accurate is this calculator? +
It's a rough estimator using 2026 bracket projections and simplified deductions (standard deduction only). Your actual liability depends on itemized deductions, the §199A QBI deduction, business deductions beyond Schedule C, credits (child tax, EITC, dependent care, etc.), prior-year tax, withholdings, and state-specific rules. Verify with a CPA before relying on the number for filing — this is an educational estimator, not tax advice.
This tool is for educational purposes only and is not an offer, approval, financial, legal, or tax advice. Tax outputs depend on your full return — consult a CPA before filing. ClearValue Lending is a funding platform.
https://clearvaluelending.com/tools/quarterly-estimated-tax-calculator