401(k) Calculator

401(k) Calculator: Maximize Your Employer-Sponsored Retirement

A 401(k) plan is one of the most powerful wealth-building tools available to American workers. Named after the section of the Internal Revenue Code that governs it, the 401(k) allows employees to contribute pre-tax dollars from their paycheck into a tax-advantaged retirement account. When combined with employer matching contributions, a 401(k) is often described as "free money" — and our calculator helps you see exactly how much that free money is worth over your career.

How 401(k) Contributions Work

In 2026, employees under 50 can contribute up to $23,500 per year to a traditional 401(k), while those 50 and older can add a $7,500 catch-up contribution for a total of $31,000. Contributions are made with pre-tax dollars, meaning a $500 contribution only reduces your take-home pay by roughly $350-$400 depending on your tax bracket. This tax deferral is one of the 401(k)'s greatest advantages — your money grows tax-free until withdrawal in retirement, when you may be in a lower tax bracket.

The Power of Employer Matching

Most employers offer some form of matching contribution, typically matching 50% to 100% of your contributions up to a certain percentage of your salary (commonly 3-6%). For example, if you earn $60,000 and your employer matches 100% up to 4%, contributing at least $2,400 per year earns you an additional $2,400 in free employer contributions. Not contributing enough to get the full match is literally leaving money on the table. Our calculator shows you the dramatic impact of employer matching on your retirement nest egg over 20, 30, or 40 years.

Investment Growth and Compounding

The real magic of a 401(k) happens through compound growth over decades. A 25-year-old contributing $500/month with a 4% employer match and 7% average annual returns could accumulate over $1.5 million by age 65. Even small increases in your contribution rate — say, bumping from 6% to 8% of salary — can add hundreds of thousands of dollars to your retirement balance thanks to compounding. Many financial advisors recommend increasing your contribution by 1% each year, especially when you receive a raise.

Traditional vs. Roth 401(k)

Many employers now offer a Roth 401(k) option alongside the traditional plan. With a Roth 401(k), you contribute after-tax dollars, but all withdrawals in retirement — including investment gains — are completely tax-free. The Roth option is particularly attractive for younger workers who expect to be in a higher tax bracket in retirement. Some financial planners recommend splitting contributions between traditional and Roth to create tax diversification in retirement.

Common 401(k) Mistakes to Avoid

Not enrolling early: Every year you delay costs you thousands in compounded growth. Cashing out when changing jobs: A $30,000 early withdrawal costs you $7,500+ in penalties and taxes, plus decades of lost growth. Being too conservative: Young investors with 30+ years to retirement should generally hold mostly stocks. Ignoring fees: High-expense-ratio funds can silently erode 20-30% of your total returns over a career — use our Investment Fee Calculator to see the impact. Taking 401(k) loans: While tempting, loans reduce your investment growth and must be repaid quickly if you leave your job.

Canadian Equivalent: RRSP and Employer Plans

While Canada doesn't have 401(k) plans, the Registered Retirement Savings Plan (RRSP) offers similar tax-deferred growth benefits. Many Canadian employers also offer Group RRSPs or Defined Contribution Pension Plans (DCPPs) with employer matching. The 2026 RRSP contribution limit is 18% of earned income up to approximately $32,490. Canadian workers should check out our TFSA vs. RRSP Calculator to determine the optimal allocation between these two powerful savings vehicles.