401(k) Calculator

A retirement projection can be useful when it reveals the assumptions behind a large future number. This page asks for a present balance, salary, contribution rate, employer-match formula, return assumption, salary-growth assumption, and retirement age. It then applies the same documented sequence each year. The result is a what-if scenario, not a prediction of a market return, retirement income, tax bill, or a recommendation to change an account.

Run more than one scenario. A lower return, a pause in contributions, a different retirement age, or a different employer-match rule can be more informative than one optimistic line. Keep the plan document next to the calculator inputs: the plan, not a generic web page, determines eligibility, compensation definitions, vesting, matching frequency, true-up provisions, Roth availability, and withdrawal rules. For a separate goal-oriented retirement estimate, see the Retirement Calculator.

Employee contributions, employer match, and growth should not be collapsed into a single percentage. The page first calculates the employee amount from salary times the entered contribution percentage, subject to its annual employee limit. It then applies the employer formula to the eligible contribution amount. Finally, it applies the entered annual return to the opening balance for that year before adding the new employee and employer amounts.

For a simple one-year illustration, an $80,000 salary with a 4% employee contribution produces $3,200 of employee contributions. If the plan matches 100% up to 4% of pay, the entered formula adds a $3,200 employer match. Starting from a zero balance, the example has $6,400 of new contributions in the first modeled year. It says nothing about the investment performance after that year.

The calculator currently applies the 2026 employee elective-deferral amounts published by the IRS: $24,500 as the base limit, plus an $8,000 catch-up amount from age 50. For participants ages 60 through 63, it applies the higher $11,250 catch-up amount when the plan permits it. That creates modeled employee ceilings of $24,500, $32,500, or $35,750 depending on age and eligibility assumptions.

These values are a limit check within the page, not proof that a participant can contribute that amount. A plan can have eligibility and compensation rules, an employee can have contributions to another plan, and other annual limits can matter. The model also keeps the 2026 values fixed over future years rather than guessing how the IRS will index them. The IRS contribution-limits page should be checked when a real contribution decision is being made.

A match formula has at least two moving parts: the percentage the employer matches and the employee contribution limit to which it applies. “100% up to 4%” means an employee contributing 4% of eligible pay can receive a match equal to 4% of eligible pay, subject to the plan. “50% up to 6%” means a 6% employee contribution can produce a 3% employer match. The same total employee contribution can therefore create a different match under a different plan formula.

Enter the match rate and cap from the plan's summary, and check whether the plan matches per payroll, annually, after a waiting period, or with a year-end true-up. This calculation does not know the answer. It also does not assume that receiving a match is universally the best next financial action; cash-flow needs, high-interest debt, emergency savings, eligibility, and personal goals are outside its scope.

The entered annual return is applied once per modeled year to the opening balance. That convention makes the math easy to inspect, but real markets do not return the same percentage each year. Contributions generally arrive throughout the year, investment choices can change, account fees can reduce results, and withdrawals or loans can interrupt compounding. Inflation also changes the future purchasing power of a balance.

Instead of asking which return is right, compare a small range and label it clearly. For example, a 4%, 6%, and 8% nominal-return scenario reveal the sensitivity of a long time horizon without implying any is promised. The Inflation Calculator can be used separately to see how an entered inflation rate changes a future amount's purchasing-power interpretation. It does not convert this page into a complete retirement-income plan.

When contributions are a percentage of salary, a salary-growth assumption changes later deposits as well as the account balance. At a starting salary of $80,000 and a 3% annual salary-growth assumption, the model raises the salary used for later contribution and match calculations. It does not claim that the user will receive raises, bonuses, promotions, or uninterrupted employment.

Compare a zero-growth and a modest-growth input if future earnings are uncertain. If a contribution percentage would exceed the model's employee limit, the page caps the contribution at that limit. Because the limit is held at its 2026 amount, a long-range projection can understate or overstate future capacity depending on later law and plan changes. This is a reason to revisit inputs rather than treat a decades-long output as settled.

A contribution changes present pay as well as a future balance. The US Paycheck Calculator can model a separate annualized paycheck scenario with an entered pre-tax contribution, while the Budget Calculator can show the cash-flow categories around it. Neither calculator knows your plan's tax treatment or tells you how to prioritize competing goals.

Use the page's Report an issue control for a reproducible formula, content, data, or accessibility issue. Include a non-sensitive age range, contribution percentage, and observed result if that helps reproduce the problem. Do not include account numbers, tax identifiers, employer portal access, or a full statement.