Solo 401(k) Contribution Calculator 2026: Max Out as Self-Employed

Calculate your 2026 Solo 401(k) max contribution as self-employed. Employee + employer limits, catch-up, Roth split. Free instant calculator.

UPDATED May 2026

<h2>The Quick Answer: Solo 401(k) Limits for 2026</h2> If you're self-employed in 2026, you can contribute up to $70,000 to a Solo 401(k) — or $77,500 if you're age 50+, and $81,250 if you're age 60–63 (thanks to the SECURE 2.0 "super catch-up"). That's split between two roles you wear simultaneously: employee (salary deferral) and employer (profit-sharing). Hitting the max usually requires roughly $233,000 in net self-employment earnings for sole proprietors, or $280,000 in W-2 wages for S-corp owners. The exact number depends on your business structure — and that's what the calculator below solves for. Author: Ziv Shay · Last updated: May 2026 <h2>2026 Solo 401(k) Contribution Limits at a Glance</h2> The IRS adjusted Solo 401(k) limits upward for 2026. Here's what changed from 2025: <ul> <li>Total annual additions: $70,000 (up from $69,000)</li> <li>Employee elective deferral: $23,500 (up from $23,000)</li> <li>Catch-up contribution (age 50+): $7,500 (unchanged)</li> <li>Super catch-up (age 60–63): $11,250 (SECURE 2.0 provision, indexed)</li> <li>Compensation cap: $350,000 (used to calculate the 25% profit-sharing piece)</li> </ul> The headline number — $70,000 — is the ceiling for total combined contributions per person, per business. If you also participate in a 401(k) at a day job, the employee deferral portion ($23,500) is shared across all plans. The employer profit-sharing portion is per-employer. <h2>How the Two-Part Contribution Math Works</h2> A Solo 401(k) lets you stack two contribution types because, as a self-employed person, you legally play both roles. Most people get this wrong on the first try because the IRS uses different definitions of "compensation" depending on your business structure. <h3>Part 1: Employee Deferral (Salary)</h3> You can defer up to $23,500 of your earned income (or 100% of comp, whichever is less). Add $7,500 if you're 50+, or $11,250 if you're between ages 60 and 63. This portion can go in as traditional (pre-tax) or Roth (after-tax), and you can split between them. <h3>Part 2: Employer Profit-Sharing</h3> You can also contribute up to 25% of compensation as the "employer." The catch: for sole proprietors and single-member LLCs, "compensation" means net self-employment income after deducting half of self-employment tax and the employer contribution itself. The effective rate works out to roughly 20% of net SE earnings, not 25%. For S-corp shareholder-employees, "compensation" means your W-2 box 1 wages — and the 25% applies cleanly to that number. <h2>Worked Example #1: Sole Proprietor, Age 42, $100,000 Net Profit</h2> Here's how the calculation runs for a freelance designer filing Schedule C: <ol> <li>Net profit (Schedule C, Line 31): $100,000</li> <li>Self-employment tax: $100,000 × 92.35% × 15.3% = $14,130</li> <li>Deductible half of SE tax: $7,065</li> <li>Net SE earnings for retirement: $100,000 − $7,065 = $92,935</li> <li>Employer contribution (effective ~20%): $92,935 × 0.2 = $18,587</li> <li>Employee deferral: $23,500 (full max)</li> <li>Total Solo 401(k) contribution: $42,087</li> </ol> That's $42,087 sheltered from current-year income tax — a roughly $10,100 federal tax savings at the 24% bracket, plus state savings. For comparison, a SEP-IRA at the same income would only allow the $18,587 employer piece — no employee deferral. <a href="/guide/sep-ira-vs-solo-401k-2026">See our SEP-IRA vs. Solo 401(k) breakdown</a> for when each wins. <h2>Worked Example #2: S-Corp Owner, Age 55, $150,000 W-2 Wages</h2> S-corp setups are cleaner because W-2 wages are unambiguous compensation: <ol> <li>W-2 Box 1 wages: $150,000</li> <li>Employer contribution (25%): $37,500</li> <li>Employee deferral: $23,500</li> <li>Catch-up (age 50+): $7,500</li> <li>Total contribution: $68,500</li> </ol> This person is just $1,500 shy of the absolute $70,000 cap (before catch-up). To max out, they'd need W-2 wages of roughly $186,000. Note: if they were age 60–63, the super catch-up bumps them to $72,250 total — pushing the limit higher because catch-ups don't count against the $70K base cap. <h2>Worked Example #3: Side Hustle While Maxing a Day-Job 401(k)</h2> This is where Solo 401(k) shines — and where most online calculators get it wrong. Suppose you earn $80,000 in W-2 wages with an employer 401(k) where you've already deferred the full $23,500, and you also net $40,000 from consulting on the side. <ul> <li>Side-business employee deferral available: $0 (already used at the day job — the $23,500 limit is per-person, not per-plan)</li> <li>Side-business employer contribution: ~20% of net SE earnings = ~$7,400</li> <li>Total side Solo 401(k) contribution: $7,400</li> </ul> The employee-deferral cap is shared, but the $70,000 total cap is per unrelated employer. So even after maxing your day-job match plus deferral, you can still stack up to $70,000 from the side business — though only the profit-sharing portion is available since deferrals are already exhausted. <h2>Roth vs. Traditional Solo 401(k): The 2026 Decision</h2> Since SECURE 2.0, the employer profit-sharing portion can also be Roth — a major change from prior years when only the employee piece was Roth-eligible. This makes the Solo 401(k) the most flexible Roth vehicle available to high earners. Rule of thumb: <ul> <li>Choose Roth if your effective tax rate is below 24% and you expect higher retirement income (early-stage business owners, those building taxable income early).</li> <li>Choose Traditional if you're at 32%+ marginal rate and plan to draw down in lower-tax retirement years.</li> <li>Split it if you're in the 24% bracket and uncertain — most people in this band benefit from <a href="/guide/roth-traditional-split-strategy-2026">a 50/50 split</a> as a hedge against future tax-rate volatility.</li> </ul> <h2>How to Use the Solo 401(k) Calculator Above</h2> The calculator at the top of this page accepts four inputs and returns your maximum allowable contribution: <ol> <li>Business type — Sole prop / single-member LLC / partnership use net SE earnings logic. S-corps and C-corps use W-2 wages.</li> <li>Net business income or W-2 wages — Pull this from Schedule C Line 31, K-1 Box 14 (code A), or W-2 Box 1.</li> <li>Age — Triggers catch-up ($7,500 if 50+) and super catch-up ($11,250 if 60–63).</li> <li>Other 401(k) deferrals already made this year — Subtracts from the $23,500 employee cap.</li> </ol> Output shows: maximum employee deferral, maximum employer contribution, total, plus the estimated federal tax savings at your marginal bracket. <a href="/guide/2026-tax-bracket-calculator">Use our tax bracket calculator</a> if you're unsure of your marginal rate. <h2>Solo 401(k) vs. SEP-IRA vs. SIMPLE IRA: 2026 Comparison</h2> Three retirement plans dominate the self-employed market. Here's the head-to-head: <ul> <li>Solo 401(k): $70K cap, allows Roth, allows loans up to $50K, requires Form 5500-EZ once balance exceeds $250K. Best for: sole owners or owner+spouse with $50K+ income.</li> <li>SEP-IRA: $70K cap, simpler paperwork, no Roth option, no loans, no employee deferral. Best for: very high earners ($300K+) who don't need the deferral piece.</li> <li>SIMPLE IRA: $16,500 deferral cap (plus $3,500 catch-up), forced 2–3% employer match. Best for: businesses with employees you don't want to enroll in a full 401(k).</li> </ul> For most solo operators with under $230K in profit, the Solo 401(k) wins because the employee deferral lets you front-load contributions even on modest income. <a href="/guide/best-solo-401k-providers-2026">See our review of low-fee Solo 401(k) providers</a> — Fidelity, Schwab, and E*TRADE all offer free plans with Roth support in 2026. <h2>Deadlines and Paperwork You Cannot Miss</h2> Two dates matter for 2026 contributions: <ul> <li>Plan establishment deadline: December 31, 2026 (for the employee deferral portion). The SECURE Act extended the deadline for employer contributions to the tax filing deadline plus extensions — but you must elect employee deferrals by year-end.</li> <li>Funding deadline: April 15, 2027 (or October 15, 2027 with extension) for the prior-year contribution.</li> <li>Form 5500-EZ: Required annually once your Solo 401(k) balance exceeds $250,000. Due July 31, 2027 for the 2026 plan year. Penalty for late filing: $250/day, capped at $150,000.</li> </ul> <h2>Common Mistakes That Cost Self-Employed Savers Thousands</h2> From audits I've reviewed, these errors show up repeatedly: <ul> <li>Using gross revenue instead of net profit. The 25%/20% calculation is based on net SE earnings, not your top-line invoice total.</li> <li>Forgetting the SE tax deduction. Skipping the "subtract half of SE tax" step inflates your maximum and can trigger excess contribution penalties (6% per year on the overage).</li> <li>Double-deferring with a day-job 401(k). The $23,500 employee deferral limit is per individual, not per plan.</li> <li>Missing the December 31 setup deadline. You can fund late, but the plan itself must exist by year-end for any deferrals.</li> <li>Skipping Form 5500-EZ. Plenty of solo operators don't realize they crossed $250K — and the daily penalty compounds fast.</li> </ul> <h2>Frequently Asked Questions</h2> <details> <summary>Can I contribute to both a Solo 401(k) and a Roth IRA in 2026?</summary> Yes — they're separate plans with separate limits. You can contribute up to $7,000 to a Roth IRA ($8,000 if 50+) on top of your full $70,000 Solo 401(k), provided your modified AGI is under $165,000 single / $246,000 married for full Roth IRA eligibility. Above those thresholds, use a <a href="/guide/backdoor-roth-ira-step-by-step-2026">backdoor Roth IRA</a>. </details> <details> <summary>What if my spouse works in my business?</summary> If your spouse earns legitimate W-2 wages or has documented self-employment income from the business, they can contribute their own $70,000 to the same Solo 401(k) — effectively doubling your household ceiling to $140,000. This is one of the most overlooked tax shelters available to family businesses. </details> <details> <summary>Can I take a loan from my Solo 401(k)?</summary> Yes. You can borrow up to 50% of your vested balance or $50,000, whichever is less. Loans must be repaid within five years (longer for primary-residence loans) at a market interest rate, typically prime + 1–2%. Default converts the unpaid balance to a taxable distribution plus 10% penalty if you're under 59½. </details> <details> <summary>What happens if I hire employees later?</summary> The "Solo" 401(k) loses its solo status the moment you hire a non-spouse employee who works 1,000+ hours/year. You'd need to convert to a standard 401(k) with non-discrimination testing, a TPA (third-party administrator), and likely $1,500–$3,000/year in admin fees. Plan your scaling timeline accordingly. </details> <details> <summary>Is the super catch-up ($11,250) automatic for ages 60–63?</summary> It's automatically allowed if your plan document supports it — but not all providers have updated their plan documents yet. Confirm with your custodian (Fidelity, Schwab, and E*TRADE confirmed support as of Q1 2026). Once you turn 64, you revert to the standard $7,500 catch-up. </details> <details> <summary>Can I contribute Roth dollars to the employer profit-sharing portion?</summary> Yes, as of SECURE 2.0. The IRS clarified guidance in late 2024, and most major custodians enabled employer-side Roth in 2025. Note: Roth employer contributions are immediately taxable as income in the year contributed, so the tax-savings math flips — you're paying tax now to lock in tax-free growth forever. </details> This content is for educational purposes only and does not constitute financial advice. Consult a qualified financial advisor or CPA before making retirement plan decisions.

About the AuthorZiv Shay is a software engineer and fintech enthusiast based in Israel, building free financial tools since 2024. Learn more

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