Solo 401(k) Contribution Calculator 2026
See the most you can stash in a solo 401(k) this year — your employee deferral plus the employer profit-sharing contribution, worked out from your net business profit.
✏️ These numbers were filled in from a shared link — change anything to make it your own.
How the maximum is calculated
- Net self-employment earnings = net profit − half your self-employment tax.
- Employee deferral — up to $24,500 in 2026 (or your earnings, if lower).
- Employer profit-sharing — 20% of your net self-employment earnings.
- Catch-up — add $8,000 at 50+, or $11,250 at ages 60–63.
- Combined employee + employer is capped at $72,000 (2026); catch-up stacks on top.
A 2026 planning estimate for sole proprietors. It simplifies self-employment tax and ignores state rules and the higher-earner Roth catch-up requirement. Not tax advice.
Frequently asked questions
How much can I contribute to a solo 401(k) in 2026?
In 2026 you can defer up to $24,500 as the "employee," plus an "employer" profit-sharing contribution of about 20% of your net self-employment earnings — up to a combined $72,000. If you're 50+ you can add an $8,000 catch-up ($11,250 at ages 60–63), pushing the max to $80,000 (or $83,250).
Why is the employer contribution 20% and not 25%?
The IRS lets an employer contribute up to 25% of compensation. But for a sole proprietor, the contribution itself reduces the compensation it is based on, so the math works out to 20% of your net self-employment earnings (net profit minus half your self-employment tax). This calculator handles that for you.
What counts as net self-employment earnings?
Your net business profit (Schedule C) minus the deductible half of your self-employment tax. The employee deferral and the 20% employer contribution are both based on that figure.
Does this work for an S-corporation?
No — this calculator is for sole proprietors and single-member LLCs taxed on Schedule C. If your business is an S-corp, contributions are based on your W-2 wages instead, and the employer share is up to 25% of those wages.
Is this tax advice?
No. It is a 2026 planning estimate that simplifies self-employment tax and ignores state rules and the higher-earner Roth catch-up requirement. Confirm with your plan administrator or CPA.