Self-Employed 401(k) Calculator 2026 — Solo 401(k) Contribution Limits

The 2026 Solo 401(k) contribution limit is $72,000 in total — combining your employee deferral (up to $24,500) and employer contribution (up to 25% of compensation). Self-employed workers under age 50 earning $120,000 in net profit can contribute approximately $46,800. The calculation is more complex than most retirement accounts because the employer contribution is based on net self-employment income after the SE tax deduction.

How the Solo 401(k) Contribution Is Calculated

A Solo 401(k) has two separate contribution buckets:

1. Employee deferral — as the employee of your own business, you can defer up to 100% of compensation up to $24,500 (2026 limit). Age 50–59 (and 64+) can defer up to $32,500; age 60–63 can defer up to $35,750 under the SECURE 2.0 “super catch-up” (this enhanced amount replaces, rather than stacks with, the standard $8,000 catch-up).

2. Employer contribution — as the employer, you can contribute up to 25% of compensation. For Schedule C filers, this works out to approximately 20% of net self-employment income (the effective rate is lower than 25% because of how net SE income is defined after the self-employment tax deduction).

Total limit: The combined amount cannot exceed $72,000 (2026) or 100% of compensation.

Step-by-Step Calculation for Schedule C Filers

Step 1: Determine net profit from Schedule C Step 2: Calculate SE tax = net profit × 0.9235 × 15.3% Step 3: SE tax deduction = SE tax ÷ 2 Step 4: Net SE income = net profit − SE tax deduction Step 5: Employer contribution = net SE income × 20% Step 6: Employee deferral = up to $24,500 (or catch-up limit) Step 7: Total contribution = employer contribution + employee deferral (cap at $72,000)

Worked Example: Freelance Designer, $120,000 Net Profit

Total federal income tax deduction: $46,804 (plus the $8,478 SE tax deduction = $55,282 total deductions from $120,000 income).

2026 Solo 401(k) Contribution Limits by Net Profit

Net profit figures. The $72,000 combined cap is reached at approximately $256,000+ net profit for a filer under 50.

Age 60–63 Super Catch-Up: Significant Advantage

Workers aged 60, 61, 62, or 63 can use the SECURE 2.0 super catch-up contribution. This raises the employee deferral to $35,750 instead of $24,500 — an extra $11,250 per year (this replaces, rather than stacks with, the standard $8,000 catch-up available at 50+).

S-Corp Owner Calculation

If you operate as an S-corporation, the math is simpler:

• Employee deferral: up to $24,500 (or catch-up) — based on your W-2 wages from the S-corp
• Employer contribution: up to 25% of your W-2 wages (no SE-tax adjustment needed since it’s W-2 income)
• The S-corp itself deducts the employer contribution as a business expense

Example: S-corp pays you a $100,000 W-2 salary.

• Employee deferral: $24,500
• Employer contribution: $100,000 × 25% = $25,000
• Total: $49,500

Solo 401(k) vs. SEP-IRA: Which Contributes More?

The Solo 401(k) always wins at lower and moderate income levels because of the employee deferral. At very high incomes (above roughly $387,000 net profit), the SEP-IRA and Solo 401(k) converge at the same $72,000 total since both are ultimately capped there.

Setting Up a Solo 401(k)

• The plan must be established by December 31 of the year you want to begin contributions
• A Solo 401(k) requires an EIN — you cannot use your Social Security Number
• Plans with over $250,000 in assets must file Form 5500-EZ annually
• Many major brokerages offer free Solo 401(k) accounts: Fidelity, Vanguard, Schwab, E*TRADE

Related Articles

• Best Self-Employed Retirement Accounts 2026
• 401(k) Contribution Limits 2026
• Catch-Up Contributions 2026: Super Catch-Up Rules
• 403(b) Calculator 2026

Written by WealthVieu

WealthVieu researches and writes data-driven personal finance guides using primary sources including the IRS, Bureau of Labor Statistics, Federal Reserve, and Census Bureau.