Self-employed plans allow large contributions. See roughly how much you can put away.
Estimates the maximum SEP-IRA or Solo 401(k) contribution from your net self-employment profit after the self-employment-tax adjustment.
For a sole proprietor, the contribution base is net profit minus the deductible half of self-employment tax, not gross profit. The employer-side limit works out to roughly 20 percent of that adjusted amount for both a SEP-IRA and the profit-sharing portion of a Solo 401(k). This is why a headline rate of 25 percent still lands near 20 percent of raw net profit for the self-employed.
A Solo 401(k) adds an employee salary deferral on top of the employer contribution, which was 23,500 for 2025, plus a 7,500 catch-up once you reach age 50. Because the deferral does not depend on the 20 percent formula, lower earners can often contribute more through a Solo 401(k) than a SEP-IRA. Total additions are still bound by an overall annual cap, and this tool gives an estimate rather than a filed figure.
The self-employed base subtracts the deductible portion of self-employment tax first, so the effective rate lands near 20 percent of raw net profit. The math produces a lower figure than a W-2 employee would see.
The 23,500 deferral limit is shared across all 401(k) plans you participate in during the year, so deferrals at a regular job reduce what you can add to a Solo 401(k). The employer portion is separate.
No, this is an estimate for planning only and does not account for every plan detail or the overall annual additions cap. Confirm your figure with a tax professional or plan administrator.
See the exact formula and a worked example on our methodology page.