Solo 401(k) Contribution Limit 2027 Self-Employed Calculator
Calculate your 2027 maximum Solo 401(k) contribution (employee deferral + employer profit-share) as a sole proprietor or single-member LLC.
2027 Solo 401(k) Contribution Limits
For 2027 (projected): Employee deferral up to $24,500 (under 50), $32,000 with $7,500 catch-up (50+), $35,250 with $10,750 super-catch-up (ages 60-63 under SECURE 2.0). Employer profit-sharing up to 20% of net SE earnings (25% of W-2 for S corp). Total combined limit (employee + employer): $73,500 (under 50) / $81,000 (50+) / $84,250 (60-63). Source: IRC §401(k), §415, SECURE 2.0 §109. Last updated: May 2026.
Solo 401(k) Math for Sole Proprietors
Sole props compute the employer portion as 20% of (net SE earnings minus 1/2 SE tax). $150K net profit × 20% ≈ $27,500 employer share (after SE tax adjustment). Add up to $24,500 employee deferral = $52,000+ total. Much more than SEP-IRA limit at the same income because the employee deferral is on top.
S Corp Solo 401(k) Differences
S corp shareholders use W-2 wages, not net SE profit. Employer share = 25% of W-2 box 1. Employee deferral = $24,500 (under 50). Reasonable comp limits this — too-low W-2 = too-low retirement contribution but also FICA savings. Run both scenarios to find optimal salary.
Why Solo 401(k) Beats SEP-IRA
At $80K-$200K SE income, Solo 401(k) typically contributes $10K-$15K MORE than SEP-IRA because the employee deferral ($24,500) is on top of the 20-25% employer share. Plus Solo 401(k) allows Roth deferrals (SEP cannot), allows loans, and (if amended for SECURE 2.0) allows in-plan Roth conversions of after-tax contributions for backdoor Roth.