How this calculator works
Each contribution year uses salary growth, the employee saving rate and the employer match per eligible employee dollar. Matching is limited to the stated salary share. The projection holds 2026 ceilings constant: $24,500 basic employee deferrals, $8,000 catch-up from age 50, $11,250 instead at ages 60 through 63, $72,000 combined additions excluding catch-up, also limited to 100% of eligible compensation, and $360,000 compensation. Annual amounts are split into monthly deposits. The withdrawal phase has its own return and growing payment assumptions. First-payment after-tax cash applies the entered income tax rate and, before age 59.5, a 10% additional tax unless the exception option is selected. Later schedule payments are gross. Vesting, future limit changes, loans, required minimum distributions and mandatory Roth treatment of certain high-earner catch-ups are not modelled. This is a simplified traditional-account scenario.
Formula
Employee annual deposit = min(eligible salary x employee rate, age-dependent deferral ceiling). Employer deposit = min(employee deposit, eligible salary x matching limit) x matching fraction, limited by the combined additions ceiling. Monthly deposit = (employee + employer) / 12. The accumulated balance then funds a withdrawal annuity.
Worked example
With a $60,000 salary, 10% employee contribution, a 50% match on the first 6% of salary and zero returns, one year adds $6,000 + $1,800 = $7,800. Ten annual withdrawals from that balance are $780 gross. At 20% income tax and no early-distribution tax, the first net payment is $624.
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Frequently asked questions
What does a 50% match up to 6% mean?
The employer contributes half of employee dollars on the first 6% of eligible salary contributed. Saving 10% of salary still receives only a 3% salary match under that formula.
Are future limits forecast?
No. The 2026 ceilings stay fixed throughout the scenario while ages move through the catch-up bands. Actual limits and plan rules can change.
Does every early payment owe an extra 10%?
No. Several exceptions exist. The calculator lets you state that an exception applies and reports additional tax only for the first payment. It does not determine eligibility or apply a blanket penalty to all future withdrawals.