401k Calculator

How the 401k calculator projects contributions and growth

A 401(k) balance at retirement is the sum of three things: the balance you already have, every dollar you and your employer add along the way, and the investment growth those dollars earn while they sit in the account. This calculator models all three. Your annual employee contribution is your salary multiplied by the contribution percentage you enter, capped at the applicable IRS limit (more on that below):

Your employer's contribution is based on the match structure you enter: a match percentage applied to your own contribution rate, up to a cap expressed as a percentage of salary, which mirrors how real employer matches are usually described in a plan document.

Once both contribution amounts are known, the calculator simulates the account month by month rather than jumping straight to a final number. Each month, one-twelfth of your combined annual employee and employer contribution is added to the running balance, and then that balance grows by one-twelfth of your expected annual return. Contributions are added before that month's growth is applied, a standard and defensible convention that treats a contribution as available to grow for the rest of the month it arrives in, rather than waiting until the following month.

A no-growth worked example. Take a salary of $60,000, a 10% employee contribution rate, an employer match of 50% up to 6% of salary, 10 years to retirement, and a 0% expected return, so the effect of contributions alone is easy to see with nothing added by growth. The employee contribution is $60,000 × 10% = $6,000 a year. The employer match applies 50% to the smaller of your 10% contribution rate and the 6% cap, so it matches on 6%, giving 6% × 50% = 3% of salary, or $60,000 × 3% = $1,800 a year. Over 10 years that is $60,000 in employee contributions and $18,000 in employer contributions. With a 0% return, no month ever grows the balance, so the projected balance is exactly $0 (starting balance) + $60,000 + $18,000 = $78,000, with zero investment growth, confirming the contribution math on its own before any return assumption is layered on top.

The 2026 IRS contribution limits and the capped-contribution example

The IRS caps how much an employee can defer into a 401(k) each year. For 2026, the standard annual employee contribution limit is $24,500. Savers who are age 50 or older by the end of the year get an additional catch-up allowance of $8,000, bringing their annual limit to $32,500. This calculator applies whichever limit matches the age you enter and never lets the projected employee contribution exceed it, regardless of how high a contribution percentage you type in. Used as a 401k contribution calculator, it also flags when your chosen rate would run into the limit.

A capped-contribution worked example. Take a salary of $500,000 and a 20% employee contribution rate. Twenty percent of $500,000 is $100,000 a year, far above either IRS limit. For someone under 50, the calculator caps the annual employee contribution at $24,500 and shows a note explaining that the limit, not the raw percentage, drove the projection. For someone age 50 or older with the exact same salary and contribution rate, the calculator instead caps at $32,500, the higher catch-up limit, since $100,000 still exceeds even that larger figure. In both cases the employer match calculation still uses your entered contribution percentage rather than the capped dollar amount, since employer matches are typically based on the contribution rate you elect on your paycheck, not on the IRS ceiling.

Two things this calculator deliberately does not do: it does not model a bonus or a change in your contribution rate over the years you enter (only the optional yearly salary increase), and it does not model the specific rules of your employer's plan, such as a vesting schedule that delays when employer contributions fully belong to you, or the fund expense ratios that quietly reduce the return you actually earn versus the return you assume here. This tool covers US 401(k) plans only, using general projection math intended for planning purposes, not as a substitute for the statements your plan provider sends you or for advice from a qualified financial or tax professional.

How much will my 401k be worth in 10 years, 20 and 30?

The table runs three saving patterns through this calculator's own projection, each from a zero starting balance with a $60,000 salary and a 7% expected annual return. Time does most of the work: in the first row, tripling the years from 10 to 30 multiplies the balance about seven times, because early contributions keep compounding. The 50% match up to 6% adds about 30% to the 30-year balance.

General pros and cons of a 401(k)

A workplace 401(k) is popular for good reasons, but it is not the right home for every dollar. On the plus side: contributions to a traditional 401(k) lower your taxable income the year you make them, an employer match is close to free money you would otherwise leave on the table, the annual contribution limit is far higher than an IRA's, and the money grows tax-deferred for decades, which is exactly what the month-by-month projection above is modelling. Payroll deduction also removes the temptation to skip a contribution, since the money never sits in your checking account long enough to get spent elsewhere.

On the downside: your investment menu is limited to whatever funds your specific plan offers, some plans carry higher administrative and fund fees than you would pay in a low-cost personal brokerage account, and your money is not easily reachable before age 59½ without triggering a penalty (more on that below). A traditional 401(k) also defers the tax bill rather than eliminating it, so every dollar you withdraw in retirement is taxed as ordinary income, which is the trade-off a Roth 401(k), covered later on this page, is built to avoid.

What a 401(k) actually invests in

A 401(k) is an account type, not an investment itself; the balance this calculator projects only grows at your assumed rate if the underlying funds you pick inside the plan actually earn it. Most plans offer a menu of mutual funds and index funds rather than individual stocks: a mix of US and international stock funds, bond funds, and increasingly, target-date funds that automatically shift from stock-heavy to bond-heavy as you approach the retirement year in the fund's name. Target-date funds have become the default option in many plans precisely because they remove the need to actively manage an allocation yourself, at the cost of a small added expense ratio compared with picking the underlying index funds directly. Whatever you choose, the expected annual return you type into this calculator should reflect your actual fund mix, not an optimistic guess, since a plan invested mostly in bonds will not realistically earn the same long-run return as one invested mostly in stocks.

How employer matching actually works

An employer match is a separate contribution your company makes on top of your own, tied to how much of your own salary you defer. The two numbers this calculator asks for, a match percentage and a match cap, mirror how a real plan document describes it: a common structure is “50% up to 6% of pay”, meaning the employer adds 50 cents for every dollar you contribute, but stops adding once your own contribution reaches 6% of salary. Contributing less than the cap leaves part of the match unclaimed entirely, which is why the standard advice is to contribute at least enough to capture the full match before directing extra savings elsewhere, ahead of even a Roth IRA in most side-by-side comparisons, since a match is an immediate, guaranteed return no market investment can promise. Comparing two runs, one at the match limit and one below it, turns this page into a 401k match calculator.

Vesting: when the employer's match is actually yours

Your own contributions are always 100% yours from the moment they land in the account, but an employer's match is often subject to a vesting schedule, a waiting period before you fully own it if you leave the company. Plans typically use one of two structures: cliff vesting, where you own 0% of the match until a specific anniversary (often three years), then jump to 100% all at once, or graded vesting, where ownership phases in gradually, such as 20% per year over five years. Leave before you are fully vested and the unvested portion of the match is forfeited back to the plan, not paid out to you. This calculator assumes every dollar of employer match it projects is eventually yours; check your own plan's vesting schedule if you are not planning to stay with your current employer for the long haul.

Early withdrawal penalties and hardship withdrawals

Money taken out of a 401(k) before age 59½ is generally hit with a 10% early withdrawal penalty on top of ordinary income tax, a combination steep enough that raiding a 401(k) early should be a last resort. There are recognized exceptions, including the “Rule of 55” (separating from your employer in or after the year you turn 55 can waive the penalty on that employer's plan specifically), and IRS-defined hardship withdrawals for a narrow list of immediate and heavy financial needs, such as preventing eviction or foreclosure, certain medical expenses, or funeral costs. A hardship withdrawal still owes ordinary income tax and, unless it also qualifies for an exception, the 10% penalty; it is not a tax-free lifeline, only a waiver of the plan's normal restriction on taking the money out at all. Many plans also allow a 401(k) loan against your own balance, which you repay to yourself with interest and which avoids the penalty entirely as long as it is repaid on schedule, typically within five years. The Early Withdrawal Costs card in the calculator above works as a 401k early withdrawal calculator and a 401k withdrawal penalty calculator in one, showing the tax, the penalty and the amount you would receive.

401(k) distributions in retirement

Once you reach 59½, you can withdraw from a traditional 401(k) without the 10% penalty, though ordinary income tax still applies to every dollar taken out, since the contributions were never taxed going in. Most people do not withdraw the entire balance at once; instead, distributions are typically taken as needed or on a planned schedule to manage the resulting tax bill across retirement years, sometimes alongside Social Security and other income sources. Leaving a job does not force an immediate decision: you can generally leave the balance in the former employer's plan, roll it into an IRA for a wider investment menu, or roll it into a new employer's 401(k) if that plan accepts incoming rollovers, each with different fee and investment-choice trade-offs worth comparing before moving anything. The Withdrawal section of the calculator works as a 401k distribution calculator, modelling either a fixed purchasing-power withdrawal or a fixed monthly or annual amount.

Required Minimum Distributions (RMDs)

A traditional 401(k) cannot be left to grow tax-deferred indefinitely. Once you reach the IRS's required beginning age, 73 for people born from 1951 to 1959 and 75 for those born in 1960 or later, you must start taking Required Minimum Distributions each year, a mandatory withdrawal calculated from your account balance and an IRS life-expectancy factor, whether or not you actually need the income. Skipping an RMD or taking less than required carries a meaningful excise tax penalty on the shortfall. Since 2024, Roth 401(k) accounts are also exempt from lifetime RMDs, matching Roth IRAs, so the old workaround of rolling a Roth 401(k) into a Roth IRA just to avoid them is no longer needed. The RMD calculator works out the yearly amount for a traditional balance.

Self-directed 401(k) plans

A small share of employer plans offer a self-directed 401(k) brokerage window, sometimes called a brokerage link, which lets you invest a portion of your balance beyond the plan's standard fund menu, in individual stocks, bonds, ETFs, or a much wider fund selection than the default lineup. It is a feature worth checking for if you want more control than a handful of target-date and index funds provides, but it also shifts more responsibility for diversification and risk management onto you, and it is a different concept from a Solo 401(k), which is a separate plan type built for self-employed individuals and small business owners with no full-time employees other than a spouse. Anyone searching for a solo 401k calculator, an individual 401k calculator, a self employed 401k calculator or a solo 401k contribution calculator needs different math: a Solo 401(k) allows both an employee deferral and an employer profit-sharing contribution, which this projection does not split.

Roth 401(k): the tax-free alternative inside the same plan

Many employer plans now offer a Roth 401(k) option alongside the traditional one, and the two can often be mixed within the same account. A Roth 401(k) contribution is made with after-tax dollars, so it does not lower your taxable income today, but qualified withdrawals in retirement, including all the investment growth, come out completely tax-free. A traditional 401(k) does the opposite: the tax break arrives today, and the tax bill arrives on withdrawal. As a rough rule of thumb, a Roth 401(k) tends to favor savers who expect to be in a similar or higher tax bracket in retirement than they are now, since paying tax at today's rate locks in that rate rather than an unknown future one; a traditional 401(k) tends to favor savers who expect a lower bracket in retirement. An employer match has traditionally been deposited on the pre-tax side of the plan even when your own contributions go into the Roth option; since the SECURE 2.0 Act, a plan may let you choose Roth treatment for the match, in which case you owe income tax on it that year. This calculator projects a single account balance and does not split the math between the two tax treatments; see the blog for a fuller worked comparison of Roth versus traditional 401(k) contributions. Anyone looking for a roth 401k calculator will find the fullest comparison there.