Solo 401(k) vs SEP IRA Calculator
See the maximum you can contribute to a Solo 401(k) versus a SEP IRA on your self-employment income — and why the Solo 401(k) usually wins.
Figures last verified: not yet verified — 2026 estimates · 2026 contribution limits
That's about $24,500 more than a SEP IRA would allow.
| Net earnings (after ½ SE tax) | $92,935.23 |
| 401(k) employee deferral | $24,500 |
| Age-based catch-up | $0 |
| Employer profit-sharing (~20%) | $18,587.05 |
| Solo 401(k) total | $43,087.05 |
| SEP IRA total | $18,587.05 |
Estimates the maximum contribution; you can always contribute less. Employer profit-sharing uses the self-employed ~20% effective rate. Excludes state rules and the mega-backdoor strategy. 2026 limits shown are unverified estimates. Not tax advice.
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How this calculator works
Who this is for
Self-employed people and single-owner businesses (no employees other than a spouse) choosing between the two most popular retirement plans. Both are easy to open, but they don't let you save the same amount.
Why the Solo 401(k) usually wins
Both plans allow an employer 'profit-sharing' contribution of about 20% of your net earnings. The Solo 401(k) lets you add an employee salary-deferral contribution on top of that — so at the same income you can usually contribute several thousand dollars more.
The gap is largest at low-to-moderate incomes, where the employee deferral is a big share of the total. At very high incomes both plans bump into the same overall limit.
Catch-up contributions
If you're 50 or older, the Solo 401(k) lets you add a catch-up contribution, and there's an even larger 'super' catch-up for ages 60 to 63. SEP IRAs don't offer catch-up contributions, which widens the Solo 401(k)'s edge for older savers.
Caveats & data freshness
This shows the maximum; contributing less is always fine. It uses the self-employed ~20% effective employer rate and 2026 limits that still need verification against IRS figures. It doesn't cover plans with employees, Roth options, or the mega-backdoor strategy. Confirm with a tax professional.
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This site is for educational purposes only and does not constitute financial advice.