Calculate your 2026 Solo 401(k) max contribution as self-employed. Employee + employer limits, catch-up, Roth split. Free instant calculator.
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
The IRS adjusted Solo 401(k) limits upward for 2026. Here's what changed from 2025:
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.
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.
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.
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.
Here's how the calculation runs for a freelance designer filing Schedule C:
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. See our SEP-IRA vs. Solo 401(k) breakdown for when each wins.
S-corp setups are cleaner because W-2 wages are unambiguous compensation:
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.
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.
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.
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:
The calculator at the top of this page accepts four inputs and returns your maximum allowable contribution:
Output shows: maximum employee deferral, maximum employer contribution, total, plus the estimated federal tax savings at your marginal bracket. Use our tax bracket calculator if you're unsure of your marginal rate.
Three retirement plans dominate the self-employed market. Here's the head-to-head:
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. See our review of low-fee Solo 401(k) providers — Fidelity, Schwab, and E*TRADE all offer free plans with Roth support in 2026.
Two dates matter for 2026 contributions:
From audits I've reviewed, these errors show up repeatedly:
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 backdoor Roth IRA.
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.
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.
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.
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.
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.
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.
The content on this page is for informational purposes only and should not be considered financial advice. Rates, terms, and offers are subject to change. We may earn a commission through affiliate links at no extra cost to you. See our full disclaimer.
© 2024–2026 AIHowToInvest.com | About | Contact | Privacy | Terms | Disclaimer