SEP IRAs look simple from the outside.

One account, one contribution rate, no employee elections to manage.

But the contribution calculation itself is more nuanced than most people expect, particularly for self-employed owners whose net earnings shrink as deductions are applied. The IRS has a specific method to handle that, and knowing how it works is the difference between contributing the right amount and dealing with a correction later.

What a SEP IRA Contribution Is Based On

A SEP IRA allows employers to contribute a percentage of compensation for eligible participants. That percentage applies cleanly for W-2 employees but becomes recursive for self-employed owners. Contribution estimates run high when calculations start from gross income instead of the IRS-defined compensation base.

The difference is straightforward at the top level. Employees use W-2 wages. Self-employed owners use net earnings after deductions. Because of that difference, self-employed owners must adjust for self-employment tax and contribution deductions before arriving at the number the IRS allows them to use.

SEP IRA Contribution Limits in Plain Terms

The IRS sets two constraints each year: a percentage limit of compensation and an annual dollar cap. For 2026, SEP IRA contributions cannot exceed the lesser of 25% of compensation or $72,000, an increase from $70,000 in 2025. The underlying contribution formula remains unchanged even as the maximum dollar amount is periodically updated.

For most scenarios, the percentage limit is what binds first, especially for lower and mid-six-figure incomes. The $72,000 dollar cap matters most for high earners whose percentage-based calculation would otherwise exceed it.

One important distinction worth noting: SEP IRAs do not allow elective salary deferrals or catch-up contributions. If the ability to make additional contributions beyond the employer contribution matters to you, a Solo 401(k) offers both.

Read more: IRS Announces 2026 401(k) and IRA Contribution Limits

How SEP IRA Contributions Work for Employees

Employee contributions are based on fixed W-2 compensation, so the calculation is straightforward. Start with W-2 compensation, apply the employer’s chosen contribution percentage, and stop if the annual IRS cap is reached.

Example: Employee earning $80,000

Step	Calculation
W-2 wages	$80,000
Contribution rate	25%
SEP contribution	$20,000

The employee calculation works cleanly because the contribution does not reduce the W-2 wages it is applied to. Self-employed calculations are different precisely because they do adjust the income they are based on.

Why Self-Employed SEP Calculations Are Different

Self-employed owners calculate SEP contributions from net earnings that shrink as deductions are applied. To keep the math consistent, the IRS uses a reduced effective rate rather than applying the stated percentage directly to net earnings.

The step-by-step process is:

1. Start with net profit from Schedule C or pass-through income
2. Subtract the deductible portion of self-employment tax
3. Apply the adjusted SEP rate
4. Confirm the result stays under the 2026 annual dollar cap of $72,000

Each step alters the income figure used in the next calculation. That is why the order matters and why skipping steps produces overcontributions.

Adjusted SEP Contribution Rates Explained

When the stated SEP rate is 25%, the effective rate for self-employed owners becomes 20%. Other rates adjust proportionally.

Stated SEP Rate	Adjusted Self-Employed Rate
25%	20%
20%	16.67%
15%	13.04%

These adjustments exist because the contribution reduces the same net earnings it is calculated from. Using the adjusted rate produces the correct number in one step without having to recalculate repeatedly.

Examples: SEP IRA Contributions at Different Net Incomes

The examples below assume a sole proprietor with no other retirement plan contributions and the SEP percentage set at the maximum allowed rate. Numbers are rounded and actual tax filings may introduce small variations.

Example 1: $50,000 net income

Step	Amount
Net income	$50,000
SE tax deduction (approx.)	$3,500
Adjusted base	$46,500
SEP contribution (20%)	$9,300

Example 2: $100,000 net income

Step	Amount
Net income	$100,000
SE tax deduction (approx.)	$7,100
Adjusted base	$92,900
SEP contribution (20%)	$18,580

Example 3: $200,000 net income

Step	Amount
Net income	$200,000
SE tax deduction (approx.)	$14,100
Adjusted base	$185,900
SEP contribution (20%)	$37,180

Example 4: $400,000 net income (dollar cap kicks in)

Step	Amount
Net income	$400,000
SE tax deduction (approx.)	$14,100
Adjusted base	$385,900
SEP contribution at 20%	$77,180
2026 dollar cap	$72,000
Actual maximum contribution	$72,000

At this income level, the percentage-based calculation produces $77,180, but the 2026 annual dollar cap of $72,000 limits the actual contribution. Any net income above approximately $360,000 will hit the cap before the percentage limit does.

How Business Structure Changes the Calculation

Your business entity determines which income the IRS treats as compensation for SEP purposes, and that directly affects how contributions are calculated.

Business Type	Compensation Used
Sole proprietor	Net earnings
Partnership	Guaranteed payments
S-corporation	W-2 wages only
C-corporation	W-2 wages

This distinction surprises many S-corporation owners. SEP contributions can only be based on W-2 wages, not on pass-through distributions. If your S-corp pays you a modest salary and takes the rest as distributions, your SEP contribution limit is based solely on that salary figure, not the total income you received from the business.

Common SEP IRA Calculation Errors

These mistakes happen repeatedly because what feels like income to a business owner is not always the number SEP rules allow you to use.

• Using gross revenue instead of net earnings
• Skipping the self-employment tax adjustment
• Applying the full stated percentage to self-employed income without adjusting
• Forgetting the annual dollar cap for high earners
• Mixing S-corporation wages and distributions in the calculation

Each mistake pushes the contribution calculation above the allowed amount, which the IRS later adjusts through corrections or penalties.

A Quick Sanity Check Before Filing

Before finalizing contributions, a simple check can catch obvious problems. Divide your SEP contribution by net earnings. If the result exceeds 20% for self-employed income, recheck the math. If you run an S-corporation, confirm the number is based on W-2 wages only.

This check works as an early filter by identifying contribution numbers that clearly fall outside allowed ranges before they become a filing issue.

Where SEP IRAs Fit Best in 2026

SEP IRAs reward simplicity. They work best when income is high, employee counts are low, and contribution flexibility is less of a priority than ease of administration.

They lose appeal when you want Roth contribution options, need employee deferral flexibility, or have income that varies sharply year to year. A Solo 401(k) often serves those situations better.

Rather than starting with contribution limits, start with your own behavior and business situation.
How stable is your income year to year? Do you want the ability to make employee deferrals? Will required employer contributions scale comfortably if you hire?

The answers to those questions point toward or away from a SEP more reliably than running the contribution math in isolation.