401k Calculator

Last Updated: June 2026

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

Annual Salary

Current 401k Balance

Your Contribution

Employer Match

Expected Annual Return

Years Until Retirement

Projected 401k Balance

Your Monthly$0

Employer/Month$0

Interest Earned$0

📐 Formula

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

How to Use the 401k Calculator

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.

Set your monthly contribution

Enter how much you contribute monthly. To convert an annual percentage to a monthly figure: Annual Salary × Contribution% ÷ 12.

Add your employer match

Input match percentage and cap. A common structure is 100% match up to 3% of salary — contributing less than 3% leaves free compensation unclaimed.

Set return rate and years

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.

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 maximising the 401(k) to the annual IRS limit: $23,500 in 2026 ($31,000 for ages 50–59 and 64+; $34,750 for the new 60–63 "super catch-up" under SECURE 2.0). Every dollar contributed reduces your current-year taxable income at your marginal rate.

The Compounding Timeline: Why Starting Early Dwarfs Amount

A 25-year-old saving $300/month at 7% accumulates approximately $940,000 by age 65. A 35-year-old saving the same amount accumulates only $454,000 — less than half — despite 30 full years of contributions. The first decade of compounding accounts for nearly half the terminal value. This is the single most important insight in retirement planning: time in the market is more powerful than amount contributed. The 401(k) calculator makes this visible instantly by adjusting the start age.

Sources & Methodology

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

Frequently Asked Questions

Q.What is the 401k contribution limit for 2024?▼

For 2026, you can contribute up to $23,500 to a 401k ($31,000 if age 50–59 or 64+; $34,750 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 $69,000.

Q.Should I contribute enough to get the full employer match?▼

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.

Q.What return rate should I use in my 401k calculator?▼

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%.

Q.What is the 401k contribution limit for 2026?▼

The 2026 401(k) contribution limit is $23,500 for employees under 50. Catch-up contributions for those 50–59 and 63–64 allow an additional $7,500. The SECURE 2.0 Act introduced a super catch-up of $11,250 for ages 60–63, bringing their limit to $34,750. Employer match contributions are additional.

Q.How much should I have in my 401k by age?▼

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 — actual needs depend on your expected Social Security income, retirement spending goals, and other assets.

Q.What happens to my 401k if I leave my job?▼

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.