Self-Employment Tax Calculator
Estimate 2026 Schedule SE self-employment tax, your deductible half, Additional Medicare Tax, simplified QBI deduction, and quarterly estimated payment.
Self-employment tax is the self-employed person's equivalent of FICA payroll tax: 12.4% Social Security (capped at $184,500 of net SE earnings in 2026 per SSA COLA announcement) plus 2.9% Medicare, on net earnings × 0.9235 (IRS Schedule SE instructions). The 0.9235 factor represents (1 − 0.0765) — it accounts for the fact that W-2 employees don't pay SE tax on the employer's half of FICA.
You can deduct half of SE tax from gross income as an above-line deduction (IRC §164(f)). Most non-SSTB self-employed workers can also deduct up to 20% of net business income as the QBI deduction (IRC §199A, made permanent by OBBB §70105).
Worked example: $80,000 net profit. Net SE earnings = $80,000 × 0.9235 = $73,880. SE tax = $73,880 × 15.3% = $11,304 (SS: $9,161 + Medicare: $2,143). Deductible half = $5,652. QBI = 20% × ($80,000 − $5,652) = $14,870.
How to use this calculator
- Enter gross business revenue and deductible expenses from Schedule C.
- Enter any W-2 wages from other jobs to correctly coordinate the Social Security wage base.
- The result shows SE tax, deductible half, additional Medicare, QBI deduction, and quarterly estimate.
Formula and assumptions
netProfit = revenue - expenses netEarningsSE = netProfit * 0.9235 SS_SE_tax = min(netEarningsSE, max(0, 184500 - W2wages)) * 0.124 Medicare_SE_tax = netEarningsSE * 0.029 SE_tax = SS_SE_tax + Medicare_SE_tax deductibleHalf = SE_tax / 2 QBI (simplified) = min(20% * (netProfit - halfSE), 20% * taxableIncome)
- SS wage base 2026
- $184,500 (SSA COLA announcement)
- SE tax rate
- 15.3% (12.4% SS + 2.9% Medicare)
- Min SE income
- $400 — below this, no SE tax owed
- QBI
- Simplified 20% — SSTB and W-2 limits not applied
Worked example
$100,000 net SE income, no W-2 wages
Limitations
- SE tax is in addition to federal income tax — both are owed.
- QBI is simplified (20% flat) — full SSTB and W-2/UBIA limits not modeled.
- State self-employment taxes not included.
- Educational estimate only — not professional tax advice.
Frequently asked questions
Self-employment tax is 15.3% on net earnings × 0.9235. The Social Security portion (12.4%) is capped at $184,500 in 2026. You can deduct half of SE tax from AGI. Most non-SSTB self-employed can claim a 20% QBI deduction under OBBB.
Recent updates
- Jan 20262026 SS wage base updated to $184,500 per SSA COLA announcement (ssa.gov/oact/cola/cbb.html).
- Jul 2025QBI deduction made permanent by OBBB §70105; removed sunset note.
- Nov 2024Initial launch with IRS Schedule SE formula and 2025 wage base.