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Solo 401(k) / SEP IRA Calculator

Compare estimated 2026 contribution room for a one-participant 401(k) and SEP IRA.

Your business information

This calculator is designed for an owner with no common-law employees eligible for the plan.

Business tax treatment 2026 Schedule C net profit ($) Age at end of 2026

Other retirement plan inputs

Employees other than you or your spouse? If eligible common-law employees exist, a one-participant 401(k) may not be appropriate; plan eligibility rules need review. 401(k)/403(b) elective deferrals at another job ($) The 2026 $24,500 employee deferral limit is generally shared across 401(k)/403(b) plans.

2026 RETIREMENT CONTRIBUTION ESTIMATE

Estimated maximum contribution shown for comparison

Solo 401(k)

Employee deferral$0

Employer contribution$0

Catch-up$0

SEP IRA

Employer contribution only$0

Employee deferral$0

Age catch-up$0

2026 limits used: $24,500 regular 401(k) elective deferral, $72,000 defined-contribution/SEP limit, $8,000 age-50 catch-up, and $11,250 catch-up for ages 60–63. For a self-employed Schedule C owner, employer contribution is estimated using the special self-employed contribution formula after the deductible portion of self-employment tax. For an S-Corp owner, retirement-plan contribution calculations are based on W-2 compensation, not shareholder distributions.

Estimate only. Results are for educational planning and are not tax, legal, or financial advice. Actual tax treatment depends on your full facts and current law.

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