Individual 401k Contribution Calculator

• How much can I contribute to an Individual 401k?

  As a self-employed sole proprietor in 2026, you can defer up to $24,500 as the employee, plus roughly 20% of your net self-employment earnings as the employer profit-sharing contribution, up to a combined $72,000 — or more with catch-up contributions. For example, a sole proprietor with $120,000 of net profit could add the full $24,500 deferral plus about $22,300 of profit-sharing, for roughly $46,800 in total. That two-sided structure lets a self-employed saver shelter far more than an employee earning the same income at a traditional job. One caveat: only the first $360,000 of compensation counts, the 20% rate applies to a sole proprietor's net earnings after half of self-employment tax, and an S-corporation owner instead uses 25% of W-2 wages.

• How is a Solo 401k contribution calculated?

  Add two pieces: the employee deferral (up to $24,500 for 2026) and the employer profit-sharing contribution — 20% of net self-employment earnings for a sole proprietor, or 25% of W-2 wages for an S-corporation owner. The combined total is capped by the §415(c) limit of $72,000, plus any age-based catch-up. For example, a sole proprietor with $80,000 of net self-employment earnings could defer the full $24,500 and add about $16,000 of profit-sharing, for roughly $40,500. Because you contribute as both employee and employer, you can shelter far more than a standard workplace plan allows. One caveat: only the first $360,000 of compensation counts toward the profit-sharing calculation, and the sole-proprietor rate is 20% of earnings after deducting half of self-employment tax, not 25%.

• What is net self-employment income for a Solo 401k?

  Net self-employment income is your net business profit (Schedule C) minus half of your self-employment tax — not your gross revenue or even your net profit directly. The employer profit-sharing contribution is calculated on this reduced figure, which is why a sole proprietor's effective rate works out to about 20% of net earnings rather than the headline 25%. For example, $100,000 of net profit becomes roughly $92,935 after subtracting half of self-employment tax, and 20% of that is about $18,600 of profit-sharing room. Your employee deferral of up to $24,500 sits on top of that. One caveat: only the first $360,000 of compensation counts, and an S-corporation owner uses a different basis entirely — 25% of the W-2 wages the business pays, not Schedule C net earnings.

• Can I have a Solo 401k and a workplace 401k?

  Yes, but the $24,500 employee deferral limit for 2026 is shared across all your 401k plans combined — a day-job plan and a Solo 401k draw from the same personal allowance, not a separate one for each. You can, however, still make employer profit-sharing contributions from your self-employment income on top of that, up to the overall §415(c) limit of $72,000 for the unrelated self-employed business. For example, if your day job uses your full $24,500 deferral, you could still add profit-sharing to a Solo 401k from freelance earnings. One caveat: the shared deferral limit is easy to breach accidentally when you switch or hold two jobs in a year, and an excess deferral can be taxed twice if not corrected, so track the combined total carefully.

• IRS-accurate formulas

  Uses the current IRS contribution limits, penalty rules and RMD tables — updated for 2026.

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