Solo 401(k) vs. SEP IRA Self-Employed Contribution Limit Calculator

Maximize self-employed retirement tax deductions across Solo 401(k) and SEP IRA rules.

Maximum Solo 401(k) Contribution
USD 51,500.00
SEP IRA Maximum Contribution USD 28,000.00
Solo 401(k) Extra Advantage USD 23,500.00
Employer Profit-Sharing Portion (20%) USD 28,000.00
Inputs
Amounts are treated in the selected currency; no foreign-exchange conversion is applied.
USD
Net Schedule C profit (after 1/2 SE tax deduction) or W-2 S-Corp wages.
USD
Employee elective 401(k) deferral limit.
USD
IRS Section 415(c) total annual additions cap.
Results & Graph
Maximum Solo 401(k) Contribution
USD 51,500.00
SEP IRA Maximum Contribution
USD 28,000.00
Solo 401(k) Extra Advantage
USD 23,500.00
Employer Profit-Sharing Portion (20%)
USD 28,000.00

Maximum Solo 401(k) Contribution

Graph 1 • Net Self Employment Profit Sensitivity Recalculates the domain equation across 50% to 150% of the primary input while holding other parameters constant.
0 USD 35.4k USD 70.7k USD 50%: 37,500 USD 37.5k 50% 75%: 44,500 USD 44.5k 75% 100%: 51,500 USD 51.5k 100% 125%: 58,500 USD 58.5k 125% 150%: 65,500 USD 65.5k 150%
Graph 2 • Primary & Supporting Metric Comparison Compares the primary output alongside supporting domain benchmarks.
Maximum Solo 401(k) Contribution USD 51,500.00 SEP IRA Maximum Contribution USD 28,000.00 Solo 401(k) Extra Advantage USD 23,500.00 Employer Profit-Sharing Portion (20%) USD 28,000.00
Graph 3 • Exact Output Table & Units Displays each calculated output in its exact domain unit.
Maximum Solo 401(k) ContributionUSD 51,500.00SEP IRA Maximum ContributionUSD 28,000.00Solo 401(k) Extra AdvantageUSD 23,500.00Employer Profit-Sharing Portion (20%)USD 28,000.00
Summary: On USD 140,000.00 net self-employment income, Solo 401(k) allows USD 51,500.00 vs. USD 28,000.00 in a SEP IRA.
Summary: On USD 140,000.00 net self-employment income, Solo 401(k) allows USD 51,500.00 vs. USD 28,000.00 in a SEP IRA.
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Formula & Mathematical Methodology: Solo 401(k) vs. SEP IRA Mathematical Formula

EmployerProfitShare = NetAdjustedCompensation × 0.20
TotalSolo401k = min(OverallCap, EmployeeDeferral + EmployerProfitShare)
EmployerProfitShare = NetAdjustedCompensation × 0.20; TotalSolo401k = min(OverallCap, EmployeeDeferral + EmployerProfitShare)
  • netSelfEmploymentProfit: Net Self Employment Profit (USD)
  • employeeElectiveDeferral: Employee Elective Deferral (USD)
  • overallDefinedContributionCap: Overall Defined Contribution Cap (USD)

Rounding: Intermediate calculations retain full IEEE-754 floating-point precision; displayed currency and ratios round to 2 decimal places.

Worked Example: Benchmark Scenario: Solo 401(k) vs. SEP IRA

Maximize self-employed retirement tax deductions across Solo 401(k) and SEP IRA rules.

  1. Enter the portfolio, option, lease, or corporate balance-sheet inputs.
  2. Evaluate the core equation: EmployerProfitShare = NetAdjustedCompensation × 0.20; TotalSolo401k = min(OverallCap, EmployeeDeferral + EmployerProfitShare).
  3. Inspect the primary valuation output, risk metrics, and 3 visual SVG graphs.
Result: Computes Solo 401(k) vs. SEP IRA using EmployerProfitShare = NetAdjustedCompensation × 0.20; TotalSolo401k = min(OverallCap, EmployeeDeferral + EmployerProfitShare).

Frequently Asked Questions

How does the Solo 401(k) vs. SEP IRA Self-Employed Contribution Limit Calculator calculate results?

It evaluates EmployerProfitShare = NetAdjustedCompensation × 0.20; TotalSolo401k = min(OverallCap, EmployeeDeferral + EmployerProfitShare) directly in your browser and updates the three domain SVG visualizations immediately as you adjust any input.

Can I compare multiple investment or financing scenarios side by side?

Yes. Click "Compare (0/3)" in the results toolbar to pin up to three scenarios side by side.

Are my financial numbers kept private?

Yes. All calculations run 100% locally in your browser with zero server uploads.

Finance & Investing · Retirement & Pensions

Solo 401(k) vs. SEP IRA Self-Employed Contribution Limit Calculator: inputs, method, and how to read the result

Maximize self-employed retirement tax deductions across Solo 401(k) and SEP IRA rules.

Choose inputs for the case you are checking

The defaults are illustrative. Replace them with values for your case and keep the units shown beside each field.

  • Display Currency: Amounts are treated in the selected currency; no foreign-exchange conversion is applied.
  • Net Self Employment Profit: Net Schedule C profit (after 1/2 SE tax deduction) or W-2 S-Corp wages.
  • Employee Elective Deferral: Employee elective 401(k) deferral limit.
  • Overall Defined Contribution Cap: IRS Section 415(c) total annual additions cap.

What the calculation includes

With the default values shown, Maximum Solo 401(k) Contribution is USD 51,500.00. The calculation follows Solo 401(k) vs. SEP IRA Mathematical Formula; the formula and variable definitions above show how the inputs combine.

One-input check: With the other defaults held constant, changing Net Self Employment Profit from 140,000 USD to 154,000 USD changes Maximum Solo 401(k) Contribution from USD 51,500.00 to USD 54,300.00. This is a comparison inside the calculator's stated model, not a prediction.

Where to use caution

  • Uses standard quantitative finance, GAAP/IFRS operating ratios, and continuous/periodic compounding conventions.
  • For educational and analytical modeling only; consult a licensed CPA, CFA, or fiduciary advisor before executing tax or derivative transactions.

Scope: Global Financial & Corporate Valuation Standard Check the assumptions and limitations against your situation before relying on the estimate.

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