401k Calculator

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Project your 401k balance at retirement. See exactly how much your employer match is worth and how much interest you'll earn over time.

Quick answer: A 401k grows through your contributions, any employer match, and compound investment returns over time. On an $80,000 salary with an 8% employee contribution and a 50%-up-to-6% employer match, the combined $8,800 saved annually compounds to roughly $556,600 after 25 years at a 7% return, per standard future-value math.

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Projected 401k Balance

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📐 Formula

Future Value = P(1+r)^n + PMT × [(1+r)^n - 1] / r, where P=current balance, r=monthly rate (return minus plan fees), PMT=monthly contribution, n=months

How to use the 401k calculator

1

Enter your current balance

Input your existing 401(k) balance. If starting fresh, enter 0. An existing balance compounds alongside new contributions; even $5,000 now significantly impacts the 30-year outcome.

2

Set your contribution and match

Enter your contribution as a percentage of salary, then your employer's match percentage. A common structure is 100% match up to 3% of salary; contributing less than 3% leaves free compensation unclaimed.

3

Set your expected return and fees

Use 7% for a historical equity average after inflation. Adjust to 5–6% for a blended stock/bond portfolio, or 8–9% for aggressive equity weighting. Add your plan's fund expense ratio in Annual Plan Fees; the calculator nets it against your return.

4

Set years until retirement

Enter how many years you have left until retirement. This single number matters more than almost any other input, since the earliest years of contributions compound the longest.

Why the employer match is your highest-return investment

An employer match provides an immediate 50–100% return on your contribution before a single dollar of market growth. If your employer matches 100% up to 3% of a $70,000 salary, contributing 3% ($2,100) earns you $4,200 in that account immediately, a guaranteed 100% return in year one. No market investment offers a guaranteed return comparable to this. Contributing less than the full match is voluntarily declining part of your compensation package.

After capturing the full match, the next priority is maximizing the 401(k) to the annual IRS limit: $24,500 in 2026 ($32,500 for ages 50–59 and 64+; $35,750 for the new 60–63 "super catch-up" under SECURE 2.0). Starting in 2026, SECURE 2.0 also requires catch-up contributions to be made as Roth (after-tax) if your prior-year wages from that employer exceeded $150,000; the rule only touches catch-up dollars, not your regular contribution. Every dollar of a regular pre-tax contribution reduces your current-year taxable income at your marginal rate. See exactly what that's worth in the Tax Calculator.

The compounding timeline: why starting early dwarfs amount

A 25-year-old saving $300/month at 7% accumulates approximately $787,000 by age 65. A 35-year-old saving the same amount accumulates only $366,000, less than half, despite 30 full years of contributions. The first decade of compounding accounts for a large share of the terminal value. This is the single most important insight in retirement planning: time in the market is more powerful than amount contributed. Try it yourself: change Years Until Retirement in the calculator above and watch the projected balance move.

How to calculate 401k growth by hand: worked example

Take an $80,000 salary, an 8% employee contribution, and a typical employer match of 50% of contributions up to 6% of salary.

Step 1: annual employee contribution. $80,000 × 0.08 = $6,400 per year, deducted pre-tax.

Step 2: the match. The employer matches half of the first 6% of salary: $80,000 × 0.06 × 0.50 = $2,400. Total flowing into the account: $8,800 per year.

Step 3: compound for 25 years at 7%. Future value of the annual stream: $8,800 × [(1.07²⁵ − 1) ÷ 0.07] = $8,800 × 63.249 ≈ $556,600.

Without the match, the same math on $6,400 alone reaches about $404,800. The match, money that required nothing but enrolling at 6% or better, accounts for roughly $151,800 of the final balance. That is the arithmetic behind the advice to never contribute below the match threshold.

How much does raising your contribution 1% actually cost?

Less than it appears, because contributions are pre-tax. Moving from 8% to 9% on $80,000 adds $800 per year to the account, but for someone in the 22% bracket take-home pay falls by only about $624; the other $176 is tax that would otherwise have gone to the IRS this year. Meanwhile that extra $800 per year compounds to roughly $50,000 more over the 25-year projection above.

Traditional or Roth 401k: which grows your spendable money more?

Does pre-tax or after-tax contribution win?

The deciding variable is your tax rate now versus in retirement. Traditional contributions skip tax today and pay it on withdrawal; Roth contributions pay tax today and withdraw free. If your bracket will be lower in retirement, true for most people whose retirement spending is below their peak salary, traditional wins. Early-career workers in low brackets, or anyone expecting higher future rates, lean Roth. Splitting contributions between both hedges the uncertainty, since nobody knows tax law 25 years out.

What happens to the match when you change jobs?

Your own contributions are always 100% yours. Employer match dollars may be subject to a vesting schedule, commonly 3-year cliff or 6-year graded. Leaving one year before a cliff vests can forfeit thousands; the vesting date belongs on the same calendar as salary negotiations when weighing a job offer.

What plan fees and the withdrawal phase do to your number

How much do 401(k) fees really cost you?

Every 401(k) charges fees through its fund expense ratios, commonly 0.3%–1.5% a year depending on the plan. Run the same $8,800/year, 25-year example above at a 1% annual fee instead of a fee-free 7% return: the projected balance drops from $556,600 to roughly $482,800, nearly $74,000 lost to a cost most participants never see itemized on a statement. Add your own plan's fee in the Annual Plan Fees field above to see the real drag.

How much can you withdraw once you retire?

A common starting point is the 4% rule: withdraw about 4% of your balance in the first year of retirement, then adjust for inflation each year after. The IRS also forces withdrawals once you reach a set age, 73 if you were born 1951–1959, 75 if born 1960 or later, whether you need the money that year or not. This calculator projects the accumulation phase only. For a full withdrawal and Social Security plan, see the Retirement Calculator.

⚠️ Disclaimer Estimates are for informational purposes only and do not constitute financial, tax, or investment advice; actual 401k growth depends on your plan's fees, investment choices, and market performance.

Frequently Asked Questions

For 2026, you can contribute up to $24,500 to a 401k ($32,500 if age 50–59 or 64+; $35,750 for ages 60–63 under SECURE 2.0). Employer contributions do not count toward this limit but do count toward the total annual limit of $72,000.
Absolutely, employer matching is free money. If your employer matches 100% up to 3% of salary, contribute at least 3%. Anything less is leaving part of your compensation on the table.
The US stock market has historically returned about 7% annually after inflation. Conservative projections use 5–6%; aggressive use 8–9%. A mix of stocks and bonds typically returns 5–7%.
The 2026 401(k) contribution limit is $24,500 for employees under 50. Catch-up contributions for those 50–59 and 64+ allow an additional $8,000. The SECURE 2.0 Act introduced a super catch-up of $11,250 for ages 60–63, bringing their limit to $35,750. Employer match contributions are additional.
Fidelity's rule of thumb: 1× salary by 30, 3× by 40, 6× by 50, 8× by 60, and 10× by 67. On a $75,000 salary: $75K by 30, $225K by 40, $450K by 50. These are guidelines, not targets; actual needs depend on your expected Social Security income, retirement spending goals, and other assets.
You have four options: leave it with your former employer (if allowed), roll it into your new employer's 401(k), roll it into a traditional IRA, or cash it out (subject to income tax and a 10% early withdrawal penalty if under 59½). Rolling to an IRA typically gives the most investment flexibility.
Ramsey recommends investing 15% of gross household income for retirement, in a specific order: contribute to your 401(k) up to the full employer match first, then max out a Roth IRA ($7,500 in 2026), then return to the 401(k) with whatever is left to reach 15%. On a $70,000 salary that works out to $2,100 to the match, $7,500 to the Roth IRA, and $900 back into the 401(k).
A common starting point is the 4% rule: withdraw about 4% of your balance in the first year of retirement, then adjust for inflation each year after. The IRS also requires minimum withdrawals starting at age 73 if you were born 1951–1959, or age 75 if born 1960 or later. See the Retirement Calculator for a full withdrawal and Social Security plan.

Sources & Methodology

Calculations are based on the most current publicly available data from authoritative government and industry sources: