Self-Employed Retirement Contribution Calculator: SEP IRA vs. Solo 401(k) vs. SIMPLE (2026)
Working for yourself means picking your own retirement plan, and the choice can more than double what you're allowed to save. Enter your profit or salary to compare a SEP IRA, a Solo 401(k) and a SIMPLE IRA side by side for 2026.
Uses 2026 IRS limits: $24,500 employee deferral, $72,000 total per plan, $17,000 SIMPLE deferral and a $360,000 compensation cap. Everything stays in your browser.
Your business and income
| Plan | Employee | Catch-up | Employer | Total | Tax saved |
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A Solo 401(k) is only for owners with no employees other than a spouse. SEP contributions must give eligible employees the same percentage, and a new SIMPLE IRA generally must be set up by October 1.
How the Calculator Works
Sole proprietors and single-member LLCs start from net profit. Self-employment tax is figured on 92.35% of profit, and subtracting half of it gives the earnings the plans use. The employer share is 20% of those earnings, the same as the 25% rate an employee's employer would use. With the default $100,000 of profit, self-employment tax is about $14,130, plan earnings are $92,935, and the employer share is $18,587.
S corporation owners use their W-2 salary instead: the employer share is 25% of salary, and the employee deferral comes out of it. Distributions don't count.
The limits. A Solo 401(k) adds your employee deferral (up to $24,500, shared with any other 401(k), 403(b), 457 or SIMPLE plan) to the employer share, up to $72,000 a plan; catch-ups come on top. At $300,000 of profit and age 55, that's $80,000: the $72,000 limit plus the $8,000 catch-up. A SEP allows only the employer share, and a SIMPLE IRA allows up to $17,000 of deferrals plus a 3% match.
Reading the Result
- The best plan is the one that lets you put away the most. A Solo 401(k) usually wins for owners with no employees; at very low profits, the SIMPLE's match on top of deferrals can edge ahead.
- Tax saved is income tax only, at your bracket. The money still counts for self-employment tax.
- Another job's 401(k) uses up the same employee limit, but the employer share of your own plan has its own $72,000 limit.
What the Calculator Leaves Out
It doesn't model employees, partnerships, multiple businesses, Roth versus pre-tax choices, the higher SIMPLE limits some small employers can offer, or state taxes, and very low profits can hit rules this simplified math doesn't capture. The $360,000 compensation cap and $72,000 limit come from IRS Notice 2025-67. For the plan-by-plan comparison, see our guide to SEP IRA vs. Solo 401(k) vs. SIMPLE IRA.