Free Agent FinanceCalculators · Interactive
Retirement Contribution Limit Calculator (SEP vs Solo 401k)
Estimate roughly how much you could contribute to a SEP IRA vs a Solo 401(k) at your income level, side by side.
This is a simplified estimate — the real SEP/Solo 401(k) employer-contribution formula involves adjustments specific to self-employment income. Verify your exact numbers with a plan provider or CPA, and confirm this year's exact limits at IRS.gov.
How this estimate works
The "employer-style" contribution — available under both a SEP IRA and a Solo 401(k) — is approximated here as roughly 20% of your net self-employment income, a commonly used simplification of the 25%-of-compensation SEP formula once you account for the self-employment tax deduction built into the real calculation. The Solo 401(k) total adds your employee deferral (and catch-up, if applicable) on top of that same employer-style portion — the SEP IRA total only includes the employer-style portion, since it doesn't have an employee deferral component. See our SEP IRA vs Solo 401(k) guide and Solo 401(k) limits guide for the full explanation.