Solo 401(k) / SEP-IRA Calculator
Estimate how much a self-employed person can contribute to a Solo 401(k) or SEP-IRA.
How self-employed contributions work
For a SEP-IRA you can contribute about 20% of your net self-employment earnings (net profit × 0.9235, minus half your SE tax). A Solo 401(k) adds an employee deferral (up to $23,500 in 2025, or $31,000 if 50+) on top of the ~20% employer portion, up to a combined 2025 cap of $70,000. This is an estimate — the IRS uses a circular calculation and exact limits depend on your situation; confirm with a CPA.
Frequently asked questions
Solo 401(k) or SEP-IRA?
At lower incomes a Solo 401(k) usually allows a larger contribution because of the flat employee deferral; at high incomes they converge near the cap.