401(k) Calculator: How Much Will Your Retirement Savings Grow?

How a 401(k) Works

A 401(k) is an employer-sponsored retirement plan that lets you contribute pre-tax dollars directly from your paycheck. Your contributions reduce your taxable income today, grow tax-deferred, and are taxed as ordinary income when you withdraw in retirement.

For 2026, the employee contribution limit is $23,500. If you are 50 or older, you can make an additional catch-up contribution of $7,500, bringing your total to $31,000 per year. These limits apply across all 401(k) accounts if you work for multiple employers.

Many employers also offer a matching contribution. A common structure is 100% match on the first 3% of salary, plus 50% on the next 2%. On a $75,000 salary, that is up to $3,750 in free money every year. Not contributing enough to capture the full match is one of the most costly financial mistakes a worker can make.

The Power of Compound Growth

The single most important factor in your 401(k) balance is not how much you earn. It is how long your money compounds. Consider this comparison for someone earning $60,000 per year contributing 10% of salary:

Start at 25: 40 years of growth at 7% average return produces roughly $1.2 million at 65.

Start at 35: 30 years of growth at the same rate produces about $567,000. Starting just 10 years later costs you more than $600,000 in retirement wealth.

Start at 45: 20 years produces roughly $245,000. That is a staggering $955,000 difference compared to starting at 25, with identical contribution rates.

This is why financial advisors universally say: contribute early, even if you can only start small. A 1% contribution at 25 beats a 5% contribution started at 40 in many scenarios.

How to Maximize Your 401(k) in 2026

Contributing enough to get the full employer match is step one. Beyond that, here is a prioritization framework most financial planners recommend:

1. Capture the full employer match. This is a 50% to 100% instant return on investment. Nothing else in personal finance competes with it.

2. Max out an IRA. Whether Roth or traditional, an IRA gives you more investment options and potentially better fees than your 401(k) plan.

3. Return to the 401(k). If you have more to save after the IRA, go back to the 401(k) up to the $23,500 limit. The tax deferral is valuable even if fund choices are limited.

If your employer offers a Roth 401(k) option, it is worth comparing to the traditional version. High earners who expect lower income in retirement usually favor traditional. Younger workers in lower tax brackets often benefit from Roth contributions.

Investment Choices Inside a 401(k)

Most 401(k) plans offer a menu of mutual funds and target-date funds. The simplest approach for most investors is a target-date fund aligned with their expected retirement year. These funds automatically shift from growth-oriented to conservative as you approach retirement.

If you prefer to build your own allocation, a common rule of thumb is to subtract your age from 110 to get your equity percentage. At 35, that means roughly 75% in stocks and 25% in bonds. At 55, it shifts to 55% stocks and 45% bonds.

Pay close attention to expense ratios. A fund charging 0.8% annually vs. 0.05% costs you thousands of dollars over a 30-year period due to the drag on compounding. Index funds in 401(k) plans typically have the lowest expenses.

What Is the Right 401(k) Contribution Rate?

A common guideline is to save 15% of gross income for retirement, including any employer match. If your employer matches 4%, contributing 11% yourself gets you there. If your employer does not match at all, 15% from your paycheck is the target.

Can not get to 15% right away? Start with at least the match threshold and increase by 1% each year, or every time you get a raise. Automating these increases so you never see the money is the behavioral trick that makes it sustainable.

Our 401(k) calculator lets you model any contribution rate and see exactly where you land at retirement. Adjust the return assumption, change the employer match, and compare starting today vs. waiting a year. The difference is almost always more than you expect.

Frequently Asked Questions About 401(k) Plans

What happens to my 401(k) if I leave my job?

You have four options: leave it with your former employer (if the plan allows), roll it into your new employer's plan, roll it into an IRA, or cash it out. Cashing out triggers income taxes plus a 10% early withdrawal penalty if you are under 59.5. Rolling to an IRA is typically the best option for most people because it preserves tax-deferred growth and gives you the widest investment choices.

When can I withdraw from my 401(k) without penalty?

Penalty-free withdrawals begin at age 59.5. Required Minimum Distributions (RMDs) begin at age 73 under current law. Taking money out before 59.5 triggers a 10% penalty plus ordinary income taxes, unless you qualify for an exception such as disability, substantially equal periodic payments (SEPP), or certain hardship provisions.

What is vesting and how does it affect my employer match?

Vesting determines when employer contributions become fully yours. Some plans vest immediately, others use a graded schedule over 2 to 6 years. If you leave before being fully vested, you forfeit a portion of your employer's contributions. Always check your vesting schedule before accepting a new job or leaving your current one.

See Where Your 401(k) Is Headed

Whether you are just starting out or trying to catch up, our 401(k) calculator projects your exact balance based on your current savings, contribution rate, employer match, and expected return. A few minutes of planning now can add hundreds of thousands to your retirement.

Try the 401(k) Calculator at FinanceToolz.com →

Find out if you are on track, and what it takes to get there.