Individual 401(k) Contribution Comparison

Compare the maximum 2026 contribution to a solo 401(k), a SEP-IRA and a SIMPLE IRA from the same business income, for sole proprietors and corporation owners. Pair this with the free 401k calculator for a fuller picture before you make a decision.

Enter your business income

2026 IRS limits

Business type

Net business profit

Schedule C line 31 (or your share of partnership earnings), before any retirement contributions for yourself.

Your age at the end of 2026

yrs

Catch-up contributions start at 50, with a larger amount at 60 to 63.

More options

401(k) or 403(b) deferrals at another job this year

The $24,500 employee deferral limit is shared across all your plans.

W-2 wages from another job

Uses up part of the $184,500 Social Security wage base, lowering your self-employment tax.

SIMPLE IRA limit

The higher limit applies automatically to employers with 25 or fewer employees that had no other retirement plan in the three years before.

Most you can contribute in 2026

Solo 401(k)

–

SEP-IRA

–

SIMPLE IRA

–

Contribution	Solo 401(k)	SEP-IRA	SIMPLE IRA
Employee deferral	–	None	–
Catch-up	–	None	–
Employer contribution	–	–	–
Total	–	–	–

How the solo 401(k) maximum is worked out

The steps of the IRS Publication 560 deduction worksheet for the self-employed, with 2026 limits and a 25% plan rate.

Net business profit–

Less the deductible half of self-employment tax–

Net earnings from self-employment–

20% of net earnings (25% plan rate ÷ 1.25)–

Employee deferral–

Employer contribution (smallest of 20% of net earnings, $72,000 less deferral, half of what is left after the deferral)–

Catch-up–

Maximum solo 401(k) contribution–

Maximum contributions at other income levels

Same business type, age and options as above.

Net profit	Solo 401(k)	SEP-IRA	SIMPLE IRA

Results are estimates for educational purposes and are not financial, tax or legal advice.