Solo 401(k) Contribution Calculator
A solo 401(k) lets self-employed people contribute as both employee and employer — often saving far more than a SEP IRA. This calculator finds your 2026 maximum based on your net profit.
How this calculator works
Your contribution has two parts. As an employee, you can defer up to $24,500 (2026), plus an $8,000 catch-up if you are 50 or older. As an employer, you can add a profit-sharing contribution of up to 25% of your net earnings — your profit reduced by half of your self-employment tax. The combined total is capped at $72,000 ($80,000 with catch-up), and cannot exceed 100% of your compensation. The calculator does all four steps for you.
Frequently asked questions
Who can open a solo 401(k)?
Anyone with self-employment income — a sole proprietor, single-member LLC, or a business owner whose only employees are themselves and a spouse. If you have other W-2 employees, a regular 401(k) or SEP IRA is usually the right choice instead.
What are the deadlines?
You must open the account by December 31 of the tax year, but you can make employee deferrals and employer contributions up to your tax filing deadline, including extensions — typically April 15.
Can I also have a Roth solo 401(k)?
Yes. Many providers offer a Roth option for the employee-deferral portion. Roth contributions are made after tax but grow and come out tax-free, giving you tax diversification in retirement.
Disclaimer: Results are estimates for general information only and do not constitute financial, tax, or legal advice. Figures reflect 2026 rules and may change. Always confirm current limits and consult a qualified professional before making decisions. Official figures: IRS.gov · 2026 limits per IRS tax inflation adjustments.