Skip to content
Ballpark TaxEst. 2026 · Free tools

Solo 401(k) contribution calculator

A solo 401(k) lets you contribute twice — once as the employee and again as the employer. At most freelance incomes that shelters far more than a SEP IRA, and this shows you by how much.

Solo 401(k) room this year

Not enough detail yet

Enter your business profit to see how much you can shelter, and how a solo 401(k) compares with a SEP IRA.

Employee deferral
Employer share
SEP IRA would allow
Solo 401(k) advantage
Business profit for the yearSchedule C net profit.
Your age50 and over get a catch-up. Ages 60 to 63 get a larger one.
401(k) deferrals already made elsewhereThe deferral limit is per person, not per plan — a day job's 401(k) uses the same allowance.
Your top federal tax bracket
Net earnings from self-employmentProfit × 92.35%.
Less half your self-employment tax
Contribution base
Employee deferral
Employer contribution20% of the contribution base for a sole proprietor.
Total you can contribute

Nothing you type leaves your browser.

Common questions

How much can I contribute to a solo 401(k) in 2026?

Up to $24,500 as an employee deferral plus roughly 20% of your net self-employment earnings as the employer, capped at $72,000 in total. If you are 50 or over you can add a catch-up on top, and ages 60 to 63 get a larger one.

Is a solo 401(k) better than a SEP IRA?

At most freelance income levels, yes — sometimes dramatically. A SEP only allows the employer contribution, so a solo 401(k) shelters up to the full employee deferral more. The gap narrows as profit rises.

Can I contribute if I also have a 401(k) at a day job?

Yes, but the employee deferral limit is per person, not per plan. Money you defer into an employer's 401(k) uses up the same allowance. The employer contribution from your self-employment is separate.

What people use next

Estimates based on published federal rules for tax year 2026. State and local tax is not included. This is general information, not advice about your situation.