Model both sides
The best planning answer often comes from comparing scenarios, not maximizing one deduction in isolation.
Free tax planning tool
Self-Employed Retirement Plan Maximizer
Compare contribution capacity, payroll dependencies, cash limits, employee complications, and when professional plan design becomes the real next step.
No account required Educational, not individualized advice
Plan-compensation screen
$245,079
Net self-employment income less an estimated one-half self-employment-tax deduction
Solo 401(k) capacity screen
$72,000
Remaining shared deferral + employer contribution + remaining applicable catch-up
SEP IRA capacity screen
$49,016
Employer contribution only; employees generally receive the same contribution percentage
Standard SIMPLE IRA screen
$24,352
Remaining shared deferral plus a dollar-for-dollar match up to 3%; enhanced SIMPLE limits are not modeled
Modeled cash-constrained maximum
$72,000
$80,000 entered owner contribution budget; employee contribution cost is not included
Cash balance plan checkpoint: compensation and cash flow may justify an actuarial design conversation, especially if the desired contribution exceeds defined-contribution capacity.
Choose and design the planEducational estimate, updated August 23, 2026. Uses 2026 limits: $24,500 shared basic elective deferral, $72,000 defined-contribution/SEP limit, $8,000 age-50 catch-up, $11,250 age-60-to-63 catch-up, and the standard $17,000 SIMPLE deferral with applicable catch-ups. The self-employed screen estimates adjusted plan compensation before applying a 20% employer rate; S-Corp employer contributions use 25% of entered W-2 pay. Enhanced SIMPLE, controlled-group, employee, deduction, and compensation-limit rules are not fully modeled.
How to use the result
Move from estimate to decision
Run alternatives, identify the assumptions driving the difference, and save the documents needed to validate the final treatment.
Check interaction effects
Income, deductions, credits, payroll, retirement, and state rules can move together.
Validate before filing
Use the result to focus review. Do not treat a screening model as a completed return.
Take the next planning step
Request a planning follow-up
Core results are free and ungated. Share your contact information only if you want Taxstra to follow up about the planning questions this tool surfaced.
Frequently asked questions
The calculator is intentionally explicit about what it does and does not decide.
Why can a Solo 401(k) exceed a SEP at lower income?
A Solo 401(k) can combine employee deferrals with employer contributions. A SEP generally relies on employer contributions only.
Can an S-Corp contribution use pass-through profit?
Retirement contributions for an S-Corporation shareholder-employee generally depend on W-2 compensation, not shareholder distributions.
Does this calculate a cash balance contribution?
No. Age, compensation history, employees, actuarial assumptions, funding range, and plan design determine that amount.