SEP IRA Contribution Limit Calculator
How to use this SEP IRA contribution calculator
This calculator estimates the maximum employer contribution you can make to a SEP IRA based on your self-employment income or W-2 compensation from your business. It is designed for sole proprietors, single-member LLC owners, and small business owners who want to understand how far they can go toward the SEP IRA contribution limit in a given tax year.
Enter your Net Self-Employment Income (Schedule C) if you are taxed as a sole proprietor, or your W-2 Compensation Paid to Yourself if you pay yourself a salary through payroll. You can also adjust the Employer Contribution Rate (%), the IRS Compensation Cap, and the overall SEP IRA contribution dollar limit for the tax year you are modeling.
The optional Solo 401(k) Employee Deferral field lets you see how much room may remain under the overall contribution dollar limit if you are also using a Solo 401(k). This is for comparison and planning only; the calculator does not file anything with the IRS.
How SEP IRA contribution limits work
SEP IRAs use employer contributions only. You do not make employee salary deferrals like you would with a 401(k). Instead, your business contributes a percentage of each eligible employee’s compensation, including your own if you are an eligible participant.
Key constraints for SEP IRA contributions usually include:
- A maximum employer contribution rate (often up to 25% of eligible compensation for common plan designs).
- An IRS compensation cap for the year (for example, the default value provided in the calculator).
- An overall annual addition limit per participant, which caps the total SEP contribution for that year.
If you are self-employed, the effective percentage of net earnings from self-employment that you may contribute is lower than the plan’s nominal contribution rate. This is because contributions are calculated on your earnings after reducing them for the deductible part of self-employment tax and the SEP contribution itself.
Core formulas at a glance
At a high level, the calculator follows these steps:
- Start with your eligible compensation: either net self-employment income or W-2 wages from your business.
- Apply the IRS compensation cap for the year.
- Multiply by your chosen employer contribution rate.
- Limit the result to the overall annual contribution dollar limit.
For a basic employer-only situation (ignoring self-employment tax refinements), the contribution formula can be written as:
where:
r= employer contribution rate (for example, 25% expressed as 0.25)C= your eligible compensation (net self-employment income or W-2 wages from your business)Ccap= IRS annual compensation cap for SEP contributions
The result is then constrained by the annual contribution dollar limit for that year.
Reading the SEP number the calculator gives you
The headline figure is the largest deductible SEP IRA contribution your business can make on your behalf for the year. The line just beneath it — the effective percentage of your compensation — is usually the more surprising number. Set a 25% plan rate on Schedule C income and the result lands closer to 18–20% of your net profit, not 25%. That gap is not a bug in the calculator; it is the reduced-rate math the IRS requires for owners who pay themselves through self-employment earnings rather than a W-2.
Two other lines help you sanity-check the estimate. The self-employment tax figure shows exactly how much was carved out of your net profit before the contribution rate was applied, and it echoes the deduction you already claim on Schedule 1. The Solo 401(k) comparison line takes the same income and stacks an employee deferral (plus an age-50 catch-up when you qualify) on top of the employer profit-sharing piece, so you can see at a glance whether switching plans would buy you meaningful extra room.
Treat the SEP figure as a ceiling, not a target. You are free to contribute less in a lean year, and because a SEP has no minimum funding requirement you can skip a year entirely. The one rule you cannot bend: whatever percentage you take for yourself is the same percentage you owe every eligible employee, so a solo owner and an owner with three staff read the identical result very differently.
A $120,000 consultant, worked line by line
Take a sole proprietor with $120,000 of net profit on Schedule C, no W-2 salary, a 25% plan rate, and the prefilled caps. It is tempting to write down 25% × $120,000 = $30,000, but that skips the two adjustments the IRS applies to self-employed owners:
- Back out half of self-employment tax. SE tax runs on 92.35% of net profit — $110,820 — at 15.3%, or about $16,955. Half of that, roughly $8,478, comes off your net profit, leaving net earnings of about $111,522.
- Switch from the plan rate to the reduced rate. A 25% plan is really 0.25 ÷ 1.25 = 20% once the contribution is measured against earnings that already exclude the contribution. Apply 20% to $111,522.
- Check the ceiling. The result, about $22,304, sits well under both the $345,000 compensation cap and the $69,000 annual limit, so nothing gets trimmed.
The calculator reports roughly $22,304 — about 18.6% of the original $120,000, which is where that "why isn't it 25%?" surprise comes from. Feed the same $120,000 into a Solo 401(k) and the picture changes: the $22,304 employer profit-sharing piece stays, but you can also defer up to $23,000 as the employee, pushing the total toward the mid-$40,000s. That extra deferral room is the main reason an owner with no employees often prefers a Solo 401(k) once income is comfortably in six figures.
SEP IRA vs. Solo 401(k) comparison
Both SEP IRAs and Solo 401(k)s are popular for self-employed individuals, but they work differently. Use the table below as a simplified comparison when interpreting your calculator results.
| Feature | SEP IRA | Solo 401(k) |
|---|---|---|
| Who can use it? | Any business with eligible employees; common for self-employed and small employers. | Generally only businesses with no employees other than owner(s) and possibly spouse. |
| Type of contributions | Employer contributions only, as a percentage of compensation. | Employee salary deferrals plus employer profit-sharing contributions. |
| Contribution rate rule | Same percentage of compensation must usually be given to all eligible employees. | Employer profit-sharing still follows nondiscrimination rules, but employee deferrals are individual choices. |
| Catch-up contributions | No catch-up contributions based on age. | Age 50+ may allow additional catch-up employee deferrals (subject to annual IRS limits). |
| Administrative complexity | Generally simpler setup and ongoing administration. | More complex; may require plan documents and, at higher balances, annual filings. |
| Best fit situations | Owners wanting simplicity and flexible employer-only contributions, especially if they have staff. | Owner-only businesses seeking maximum flexibility and higher potential total contributions. |
The calculator does not replace a full Solo 401(k) projection, but it helps you gauge whether a SEP IRA alone will likely satisfy your retirement saving goals at your current income level.
Where the estimate stops and your CPA starts
This is a planning tool, not tax advice, and a few of its shortcuts matter enough to name out loud before you fund an account:
- Self-employment tax is flat 15.3% here. In reality the 12.4% Social Security portion stops at the annual wage base (well into six figures), so once your net earnings clear that threshold the tool slightly overstates your SE tax and therefore understates your contribution by a small amount. It errs on the conservative side.
- It sizes only your own contribution. A SEP must give every eligible employee the same percentage you take. If you have staff — generally anyone 21 or older who worked for you in three of the last five years — your real cash outlay is this figure multiplied across the payroll, which can flip a SEP from cheap to expensive fast.
- The caps are frozen to one tax year. The $69,000 limit and $345,000 compensation cap are prefilled for a single year and drift with inflation. Overwrite them with the current-year figures before you rely on the output.
- Nothing here checks eligibility or aggregation. It will not tell you whether you qualify for a Solo 401(k), and it does not combine limits across a second job's 401(k) or a spouse's plan, where separate aggregation rules apply.
For the actual number you deposit and deduct, run it past a tax professional against the current IRS Publication 560 worksheet for your filing year.
From estimate to a funded account
Once the number looks right, the practical timeline is what saves you money. A SEP IRA is unusually forgiving on timing: you can open and fund it as late as your business tax-filing deadline, extensions included, which means an owner filing an extended return in the autumn can still make a contribution that counts for the prior tax year. That flexibility lets you wait until the books are closed and your actual net profit is known before committing cash.
A short punch list before you deposit:
- Re-run the estimate with your final Schedule C or W-2 figure rather than a mid-year projection — the contribution moves dollar-for-dollar with net profit.
- Confirm the current-year compensation cap and $69,000 limit, then adjust your quarterly estimated tax payments to reflect the deduction you plan to take.
- If you have any employees, budget for their contributions at the same percentage before you lock in your own rate.
- If the Solo 401(k) comparison line is meaningfully higher and you have no employees, it may be worth pricing out that switch with your provider before you fund the SEP.
Owners with multiple entities, common-law employees, or an existing 401(k) elsewhere have coordination rules this tool doesn't model — that's the point to bring a tax advisor into the loop.
How the SEP IRA Contribution Limit Works
Simplified Employee Pension (SEP) IRAs remain one of the most flexible retirement plans for self-employed professionals, freelancers, and small business owners. The plan allows the business to make employer contributions up to 25% of eligible compensation, capped at an annual dollar limit that adjusts each year with inflation. For 2024, the dollar cap is $69,000 and the compensation limit is $345,000. Unlike Solo 401(k) plans, SEP IRAs do not support employee salary deferrals, but they are exceptionally easy to administer and require minimal paperwork. This calculator automates the formula the IRS uses to determine how much a business can contribute on behalf of an owner, incorporating the nuanced adjustments for self-employment tax. Without those adjustments, many entrepreneurs inadvertently overfund their accounts, risking penalties or remedial contributions.
The starting point is net self-employment income, typically the bottom line from Schedule C or Schedule F. Self-employed individuals must first reduce that figure by half of their self-employment tax, which the IRS treats as the employer’s share of Social Security and Medicare. The calculator multiplies net income by 92.35% to approximate the earnings subject to self-employment tax, applies the 15.3% rate, and subtracts half of the result from the original net profit. The second, easy-to-miss step is that the plan rate itself has to be converted to a reduced rate before it touches those net earnings: a 25% plan becomes 0.25 ÷ 1.25, or 20%, because the contribution shrinks the very base it is measured against. Applying 20% rather than 25% is what keeps self-employed owners from quietly overfunding their accounts. W-2 wages paid to an owner behave differently — an S corporation shareholder’s salary takes the full plan rate, so the calculator handles the two income types on separate tracks and adds them together.
Integrating IRS Compensation Caps
Even after adjusting for self-employment tax, contributions cannot exceed the IRS compensation cap. For 2024, any compensation above $345,000 is ignored when calculating SEP contributions. The calculator applies this cap automatically, so high-income professionals can immediately see the maximum benefit. This feature also helps accountants performing year-end planning for physicians, consultants, and creative agencies with variable income. By capping the compensation input, the tool maintains compliance without requiring users to memorize IRS thresholds.
Comparing SEP IRAs and Solo 401(k)s
SEP IRAs shine when income is high and the owner wants to maximize employer contributions without the complexity of a 401(k). However, entrepreneurs with moderate income might achieve higher total contributions by pairing a Solo 401(k) with employee salary deferrals. The calculator therefore includes an optional field for employee deferrals to illustrate the Solo 401(k) potential. It assumes the user contributes the maximum deferral allowed for their age—$23,000 in 2024 for those under 50 and $30,500 with the catch-up for those 50 or older. By displaying both the SEP contribution and the hypothetical Solo 401(k) total, the calculator empowers users to choose the most advantageous plan for their circumstances.
Age plays a subtle role as well. While SEP IRAs do not have catch-up contributions, Solo 401(k)s do. The calculator flags when a user is 50 or older and indicates how the catch-up could increase the employee deferral limit. This reminder helps financial planners demonstrate the value of switching plans or maintaining both a SEP and a Solo 401(k) for different lines of business.
Why the SEP rate and the compensation cap rarely bind at the same time
Two ceilings sit on top of the percentage math, and which one bites depends entirely on your income. The compensation cap ($345,000 in the prefilled year) matters only for high earners: multiply it by the 20% reduced rate and you land almost exactly on the $69,000 annual limit, so above roughly $345,000 of net earnings your contribution is frozen regardless of what rate you type. Below that, the percentage is what governs, and the cap never enters the picture. This is why a $90,000 sole proprietor and a $400,000 one experience the calculator so differently — the first is limited by a rate on a modest base, the second is simply parked at the flat dollar ceiling. Knowing which lever controls your number tells you whether earning more will actually raise your contribution room or just pad income the plan already ignores.
Timing quirks worth planning around
Because a SEP is funded by the employer, its deadline follows the business return rather than the April IRA cutoff. A sole proprietor who extends to October can still make a prior-year contribution in the autumn, and can wait until the books are final to decide the exact amount — a genuine cash-flow advantage over plans that lock at year-end. The trade-off is discipline: money that could have compounded all year often sits uninvested until the deadline. If your income is stable, funding steadily through the year captures more market time; if it swings, the late deadline is the safety valve that lets you match the contribution to a year you can actually afford.
Running scenarios for an S corporation owner
The W-2 field is where S corporation owners get the most out of this tool. Because the SEP contribution on wages uses the full plan rate rather than the reduced one, the salary you set for yourself directly drives your contribution room — but only up to a point. Raise your W-2 wage and the potential SEP deposit climbs with it; the catch is that every extra dollar of salary also carries payroll tax, so there is a sweet spot where a modest salary bump buys real retirement room without lighting up your FICA bill. Toggle the net-income and W-2 fields against each other to see how the same total profit splits differently depending on whether you take it as distributions or wages. It is a quick way to pressure-test a salary decision before you commit to it on the corporate return.
Checklist for Implementing a SEP IRA
To convert the numbers into action, the explanation now incorporates a step-by-step checklist that mirrors the IRS setup process. First, select an approved financial institution and execute IRS Form 5305-SEP or an equivalent prototype agreement. Next, communicate eligibility and contribution percentages to all employees who meet age and service requirements, typically those over 21 who worked for the business in three of the last five years. Then, calculate contributions for each eligible participant using the same percentage derived for the owner, deposit funds by the tax filing deadline (including extensions), and provide annual statements summarizing contributions. The 5305-SEP is a one-page form you keep on file rather than mail to the IRS, which is a large part of why the SEP is the least paperwork-heavy plan an owner can run.
The added content also highlights coordination with tax filings and bookkeeping. Business owners are reminded to record contributions as employer expenses, adjust estimated tax payments to reflect the deduction, and retain payroll documentation showing how the contribution percentage was applied uniformly. Where the deduction lands on the return depends on the entity: a sole proprietor’s own SEP contribution flows to Schedule 1, while an S corporation or partnership deducts contributions made for the owner-employee on Form 1120-S or Form 1065. Custodians, meanwhile, report deposits to participants on Form 5498, so keep those alongside your own records in case the amounts ever need to be reconciled.
Arcade Mini-Game: SEP IRA Contribution Limit Calculator Calibration Run
Use this quick arcade run to practice separating useful scenario inputs from common planning mistakes before you rely on the calculator output.
Start the game, then use your pointer or arrow keys to catch useful inputs and avoid bad assumptions.