SEP IRA contribution calculator for 2026
Put in your net profit and see the most you can contribute to a SEP IRA and to a solo 401(k) for 2026, worked the way IRS Publication 560 works it.
Your numbers for 2026
How the SEP contribution is worked out
A SEP plan can take up to 25 per cent of pay. For a self-employed person, "pay" is net earnings from self-employment, which is the net profit less the deduction for half of self-employment tax, and the contribution is itself deducted from it. Publication 560 handles that by reducing the rate: a 25 per cent plan rate becomes 20 per cent of the profit after the self-employment tax deduction.
So on a net profit of $100,000: self-employment tax is $14,129.55, half of it is $7,064.78, and 20 per cent of the remaining $92,935.22 is $18,587.04. That is the most that can go into a SEP IRA, and the calculator above does the same sum with your figures.
A solo 401(k) allows the same 20 per cent as the employer, and on top of it up to $24,500 deferred as the employee, which is why it holds more at most incomes below the ceiling. On the same $100,000 profit that is $18,587.04 plus $24,500, or $43,087.04. Both plans stop at $72,000 a year before catch-up contributions.
The 2026 limits used here
| Limit | 2026 | Source |
|---|---|---|
| Most that can go into a SEP IRA or a solo 401(k), before catch-up | $72,000 | IRS Publication 560, Notice 2025-67 |
| Most pay a contribution can be worked out on | $360,000 | IRS Publication 560, Notice 2025-67 |
| Employee deferral into a 401(k) | $24,500 | Notice 2025-67 |
| Catch-up at 50 and over | $8,000 | Notice 2025-67 |
| Catch-up at 60, 61, 62 and 63 | $11,250 | Notice 2025-67 |
| Earnings that carry the 12.4% Social Security tax | $184,500 | Social Security Administration |
This is arithmetic, not tax advice: it assumes a sole proprietor or single-member LLC with one business, taxed on Schedule C, and no other retirement plan. A partnership, an S corporation or a second plan changes the sums. Check the result against Publication 560's Deduction Worksheet for Self-Employed, or with whoever does your return.