Solo 401(k) Contribution Calculator (2026)

Your numbers

Estimates 2026 Solo 401(k) max contributions for a self-employed sole proprietor. Elective deferral limit $24,500; age 50+ catch-up $8,000 (50–59 or 64+); ages 60–63 enhanced catch-up $11,250; combined annual additions $72,000 (catch-ups excluded from that base); compensation limit $360,000; SE Social Security wage base $184,500. Employer profit-sharing uses the Pub 560 reduced-rate method (same as SEP). Sources: IRS COLA / Notice 2025-67, Publication 560. Compare with the SEP IRA contribution calculator; check SE tax with the self-employment tax calculator; fund each invoice with the tax set-aside calculator.

Track profit so the contribution math is real

The Freelancer Income & Quarterly Tax Tracker logs invoices and expenses so your Schedule C profit (and this Solo 401(k) estimate) stay current through the year. Excel and Google Sheets, instant download.

Questions

Solo 401(k) vs SEP IRA — which lets me contribute more?

A Solo 401(k) lets you make employee elective deferrals (up to $24,500 in 2026, plus catch-up if eligible) on top of an employer profit-sharing contribution. A SEP is employer-only. At the same profit, a Solo 401(k) usually allows a higher total because of the employee deferral.

What are the 2026 Solo 401(k) limits?

Elective deferral $24,500; age 50+ catch-up $8,000 (ages 50–59 or 64+); ages 60–63 enhanced catch-up $11,250; combined annual additions $72,000 before catch-ups ($80,000 with age 50+ catch-up, $83,250 with 60–63). Compensation counted toward the employer piece is capped at $360,000.

How do the catch-up age bands work?

Under age 50: no catch-up. Ages 50–59 or 64+: standard $8,000 catch-up. Ages 60–63: the SECURE 2.0 enhanced catch-up of $11,250. Catch-ups sit on top of the $72,000 annual-additions base.

When are contributions due?

Employee elective deferrals for the calendar year are generally due by December 31. Employer profit-sharing contributions can often be made by your tax filing deadline, including extensions. Confirm with your plan custodian.

Is this tax or investment advice?

No. It is a free planning calculator for a sole proprietor with no employees, based on general 2026 IRS limits. Entity type, other plans, plan documents, and your situation can change the result. Talk to a tax professional.