Solo 401(k) Contribution Calculator (2026)
A solo 401(k) lets a self-employed owner contribute in two roles. As the employee you can defer up to $24,500 in 2026; as the employer you can add about 20% of net self-employment earnings. The combined cap is $72,000 ($80,000 if you are 50 or older). On $100,000 of net profit, that is roughly $24,500 + $18,600 = $43,100. Enter your profit below.
What is the solo 401(k) limit for 2026?
Up to $24,500 as the employee, plus an employer contribution of about 20% of net self-employment earnings, to a combined limit of $72,000 (plus catch-up if 50+).
How is the employer contribution calculated?
For a sole proprietor it is about 20% of net self-employment earnings (net profit minus half the self-employment tax), reflecting the 25%-of-compensation rule.
What is the catch-up for 2026?
If you are 50 or older you can add $8,000, raising the combined limit to $80,000. A higher catch-up applies at ages 60-63.
Who can open a solo 401(k)?
Self-employed individuals and business owners with no full-time employees other than a spouse. It allows much larger contributions than a SEP or IRA at lower incomes.
How does a solo 401(k) work?
A solo 401(k), also called an individual 401(k), is a retirement plan for a self-employed person or a business owner with no full-time employees other than a spouse. Its advantage is that you contribute as both the employee and the employer, which lets you save far more than an IRA or, at modest incomes, a SEP.
- As the employee, defer up to $24,500 of earnings (the 2026 elective limit).
- As the employer, add about 20% of your net self-employment earnings.
- Keep the combined total at or below the $72,000 limit for 2026.
- If you are 50 or older, add the $8,000 catch-up on top.
What are the 2026 solo 401(k) limits?
The IRS sets an employee deferral limit and an overall 415(c) limit each year. The table shows the 2026 figures.
| Limit | 2026 amount |
|---|---|
| Employee elective deferral | $24,500 |
| Combined employee + employer (415(c)) | $72,000 |
| Catch-up (age 50+) | $8,000 |
| Combined limit with catch-up | $80,000 |
How is the employer contribution calculated?
For a sole proprietor or single-member LLC, the employer contribution is 25% of compensation — but because the contribution itself reduces the base, the effective rate works out to about 20% of net self-employment earnings, which is net profit minus the deductible half of your self-employment tax. The calculator handles this reduced-rate math for you, so the employer figure it shows is the IRS-correct amount, not a naive 25% of profit.
Is a solo 401(k) better than a SEP IRA?
At higher incomes both plans can reach the $72,000 limit, but at lower and middle incomes the solo 401(k) wins because of the employee deferral. A SEP only allows the ~20% employer-style contribution, so on $60,000 of profit a SEP caps out near $12,000 while a solo 401(k) can reach roughly $24,500 plus the employer piece. The solo 401(k) also allows Roth contributions and catch-ups. Compare your overall tax picture with our self-employed tax calculator.