Tax & Payroll
Solo 401(k) Contribution Calculator (2026)
Combine employee deferrals and employer profit-sharing to find your 2026 Solo 401(k) maximum.
Preparing your result…
What this calculator does
Shows maximum Solo 401(k) contribution.
What your result means
Employee plus employer contributions.
Formula
Employee = min($24,500 + catch-up − other deferrals, compensation). Employer = 20% × (profit − ½ SE tax) or 25% × W-2. Total ≤ $72,000 + catch-up
The step-by-step working for your own numbers appears with the result above and in the PDF report.
Frequently asked questions
Symbols and assumptions
- C
- Compensation
- • 2026: $24,500 deferral, $8,000/$11,250 catch-up, $72,000 cap.
Sources and review
Reviewed 2026-09-23 · Next review 2027-01-15
- • Roth vs pre-tax split not modelled.
- • Rules change annually.
- • Educational estimate, not tax advice.
Important limitation
This is an educational estimate based only on the values and formula shown. Verify current rates, rules, units, and professional standards before relying on the result. It is not personalized financial or investment advice.
Report a mistake or request an improvement
Tell us if a formula, unit, explanation, or result needs attention. Your message will include this calculator’s name and page.
Related calculators
401(k) Early Withdrawal Penalty Calculator (IRC §72(t))
See how much of an early 401(k) withdrawal you keep after income tax, state tax and the 10% penalty.
401(k) Employer Match Optimizer (2026)
Find the contribution rate that captures your full employer match within the 2026 IRS limit.
Health FSA Contribution & Use-It-or-Lose-It Calculator (2026)
Size your 2026 health FSA election: tax saved versus money at risk if you don't spend it.
Roth IRA 5-Year Rule & Distribution Ordering Checker
See which part of a Roth IRA withdrawal is contributions, conversions or earnings — and what is taxed or penalised.
Roth IRA Contribution Limit & Phase-out Calculator (2026)
See how much you can contribute to a Roth IRA in 2026 based on income and filing status.
SEP IRA Contribution Limit Calculator (2026)
Find the maximum 2026 SEP IRA contribution for a self-employed owner or an employee paid on W-2.