Interactive Planning Tool

Solo 401(k) vs. SEP IRA Analyzer

For owner-only businesses — S-corp owners, sole proprietors, and single-member LLCs with no employees other than a spouse. See the extra room a Solo 401(k) gives you over a SEP IRA, what each saves in tax this year, and what they're worth later on equal cash, under 2026 rules.

Visual Explainer

How a Solo 401(k) Unlocks Up to $72,000+ vs. a SEP IRA

S-CORP W-2 SALARY $150,000 Plan compensation base SEP IRA (EMPLOYER ONLY) $37,500 max No employee side · Triggers IRA Pro-Rata SOLO 401(K) (2-SIDED + MEGA) $62,000 standard · $72,000 Mega $24,500 Employee + $37,500 Employer + $10,000 Mega Roth YEAR 20 AFTER-TAX $219,050 +$81,200 ahead of SEP IRA
Calculating...
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1Your Business
Plain-English inputs — click any i to see what a term means.
S-Corporation: Max annual additions ceiling $72,000
S-Corp: Box 1/3 W-2 wages. Sole Prop: Schedule C Line 31 net profit.
Does NOT count toward plan contributions, but affects your marginal tax bracket.
All pre-tax IRA custodians combined as of Dec 31. Non-zero balance triggers the Backdoor Roth Pro-Rata trap.
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Side-by-Side Contribution Ceiling

SEP IRA Max
$37,500
Solo 401(k) Standard
$62,000
Solo 401(k) + Mega Backdoor
$72,000
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Line-by-Line Breakdown

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Hidden Tax Traps Radar

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Optimal S-Corp W-2 Salary Solver (For Max Tax-Advantaged Capacity)

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Advisory Fees

Advisory fees are set by CleverAlpha's Form ADV Part 2A
$0
20-year horizon
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Your Step-by-Step Playbook

Step → Open Solo 401(k)

Open a CleverAlpha Solo 401(k)

Owner-only 401(k) with Charles Schwab custody. Pre-tax and Roth employee deferrals; pre-tax or Roth employer contributions. See our fee schedule and plan features before opening.

Get started →
Related → Rollover Analyzer

Already Have a SEP IRA?

Use our Rollover Analyzer to execute a trustee-to-trustee Reverse Rollover from your SEP IRA into a Solo 401(k) and clear the way for a backdoor Roth IRA with no pro-rata tax.

Open Analyzer →