401(k) Calculator

Before you enter your numbers

Check the match formula in your plan document. A 50% match on contributions up to 6% of salary means the employer can contribute up to 3% of salary; it does not mean a 6% employer contribution. Enter annual salary growth separately from the investment-return assumption.

• Current 401(k) balance
• Annual salary
• Employee contribution rate
• Employer match rate
• Years to retirement
• Expected return
• Salary growth

Input reference

• Current 401(k) balance: The current balance committed to this goal. Use a recent statement and exclude money reserved for unrelated goals. This starting value is already invested, so do not also enter it as a recurring contribution.
• Current age: Your age at the start of the projection. This determines how long contributions can compound before the selected retirement date; it does not set legal access to a pension or retirement account.
• Years to retirement: The duration of the calculation in years. Longer periods give growth or withdrawals more time to operate. This is a chosen modeling horizon, not a prediction of an investment term or your lifetime.
• Annual return: An assumed nominal annual rate, divided by 12 in monthly projections. It is held constant. It is not a guaranteed yield, and the default should be replaced with an assumption suited to your scenario.

Formula and calculation method

The model calculates employee deferrals from salary and the elected percentage, caps them at the stored age-based planning limit, and matches the actual capped contribution subject to the salary cap. Contributions are spread across month-end deposits. Salary increases annually, and age-based catch-up eligibility is updated each modeled year.

Worked example

With an 80,000 salary and a 6% employee contribution, annual employee saving is 4,800. A 50% match up to 6% of pay adds 2,400. Together they contribute 7,200, or 600 monthly, before investment growth.

How to interpret the result

The result panel reports projected 401(k) balance, employee contributions, employer contributions and estimated investment growth.

The 2026 standard employee limit is 24,500, with 8,000 catch-up for eligible participants age 50 or older; the special age-60-to-63 catch-up is 11,250 instead. Future statutory limits are held at 2026 amounts. The model does not enforce the combined employer-and-employee ceiling, compensation limits, vesting, payroll true-ups or tax treatment of catch-up contributions.

How the 401(k) employer match is calculated

The calculator first caps actual employee deferrals, then limits the effective contribution percentage to the employer’s match cap, then applies the employer match rate to that eligible contribution. For example, a 50% match up to 6% of salary means an employee contributing at least 6% receives an employer contribution equal to 3% of salary.

Employee deferrals are also capped at the 2026 planning limit for the entered age. The model uses 24,500 as the basic limit, adds the standard catch-up for age 50+, and applies the higher 60–63 catch-up where relevant. Your actual employer plan can impose lower limits or a different matching formula.

Payroll timing and match rules

This model spreads contributions evenly across the year. A plan that matches each paycheck can produce a different result if you reach the employee limit early and stop contributing before year end. Some employers provide a true-up; others may not. Check the actual plan document and payroll schedule.

Keep employee deferrals, employer match and investment growth conceptually separate. A match can improve your total account value even in a flat market. The investment-return field should reflect portfolio performance alone rather than incorporating employer contributions as an extra return percentage.

Use your plan document for the match, not a rule of thumb

Employer matches are plan-specific. A formula such as “50% of contributions up to 6% of pay” is different from a flat 3% employer contribution. Enter the match rate and match ceiling that match your actual plan, and remember that vesting can determine how much employer money you keep after leaving the job.

If you expect to reach the annual employee contribution limit, payroll timing matters. Some plans match each paycheck and some provide a year-end true-up. The projection is most useful as a long-term estimate, while the plan document and payroll system remain the source of truth for the exact annual match.

Use The Result In The Next Calculation

After projecting the 401(k) balance, convert it into retirement income with the 401(k) withdrawal calculator or combine it with IRA, pension and Social Security estimates in the main retirement calculator. Keep employee and employer contributions separate when checking the result.