Small Business Planning Tool
Small Business Retirement Plan Calculator
See which plan lets you save the most. Enter your income and age to compare the maximum 2026 contribution under a SEP IRA, SIMPLE IRA, and Solo 401(k), side by side.
No sign-up required · Instant results
Business Type
Your business net profit before the retirement contribution.
Catch-up contributions apply at 50+, with an enhanced catch-up at 60–63.
This is an estimate, not a number to plan around alone.
This calculator is an educational tool to help you think through scenarios. The results are illustrative estimates based on the inputs you provided and general assumptions. They are not financial advice, and the numbers shown should not be relied on as exact to your situation.
Real outcomes depend on factors a calculator can't fully model: your complete tax picture, plan-specific rules, market performance, IRS rate changes, life events, and how all the pieces of your financial life interact. Past performance does not guarantee future results.
This tool does not collect, store, or transmit any financial data.
This tool assumes an owner-only business and applies the self-employment-tax adjustment for sole proprietors. Contribution limits, eligibility, and the exact self-employed calculation depend on your entity type and facts, and change annually. Verify current figures with your CPA and at irs.gov.
Before making any decision based on these numbers, let's talk. I'll look at your full picture, pressure-test the assumptions, and help you understand what these numbers actually mean for you, at no cost.
By Jay Chang, VP, Wealth Advisor
Last updated July 18, 2026
What This Calculator Compares
It estimates the most you can contribute in 2026 under the three main small business retirement plans, a SEP IRA, a SIMPLE IRA, and a Solo 401(k), at your income and age. For an owner-only business, the numbers can differ by tens of thousands of dollars, and the plan you choose is the whole reason why.
The Solo 401(k) usually wins because it lets you contribute as both the employee, a salary deferral, and the employer, a profit-sharing contribution. A SEP allows only the employer piece. A SIMPLE has lower limits but is easy to run for a small team. The full decision, including employees, is on the small business retirement plans page.
How to Use It
- Choose your business type. Sole proprietor and LLC owners enter net self-employment income; S-corp owners enter their W-2 wages.
- Enter your income and age. Age drives the catch-up contributions available at 50 and older.
- Read the comparison. The plan with the tallest bar lets you shelter the most at your income.
Questions I Hear Most
Which plan lets me contribute the most?
For an owner-only business, usually the Solo 401(k), because it stacks a salary deferral on top of an employer profit-sharing contribution. A SEP allows only the profit-sharing piece, and a SIMPLE has lower limits. All three cap at the 2026 total-additions limit of $72,000. The SEP vs SIMPLE vs Solo comparison walks through why.
Why is the self-employed number lower than 25% of my income?
For a sole proprietor, the contribution is based on net self-employment income reduced by half of your self-employment tax, and the effective employer rate works out to 20% rather than 25%. This calculator applies that adjustment automatically. An S-corp owner contributes based on W-2 wages at 25%.
What if I have employees?
Then the picture changes. A Solo 401(k) is only for an owner-only business, and a SEP or SIMPLE requires employer contributions for eligible employees too. Once you have a team, a 401(k) with a designed match often fits better. The IRS keeps plain pages on SEP and one-participant 401(k) plans.
Ready to set one up?
The calculator shows the ceiling. I help you actually reach it.
I match the plan to your business, serve as the 3(38) investment fiduciary, and coordinate the setup with your CPA so the contribution is sized and funded correctly.