401k Retirement Calculator

Project your 401k savings growth with employer match, salary increases, and compound returns. Plan your US retirement with confidence.

Calculate Your 401k Growth

The 2024 401k contribution limit is $23,000 ($30,500 if age 50+). Employer match is free money — always contribute at least enough to get the full match.

IRS limit: $23,000/year (2024). Capped automatically.
e.g., 50% match = for every $2 you put in, employer adds $1
Employer matches up to this % of your salary (typically 3–6%)
Historical S&P 500 avg: ~10% (7% inflation-adjusted)

What is a 401k?

A 401(k) is a tax-advantaged retirement savings account offered by US employers. Contributions are made pre-tax (Traditional 401k) or after-tax (Roth 401k), reducing your taxable income. The account grows tax-deferred until withdrawal at retirement age (59½+).

2024 401k Contribution Limits

Traditional vs Roth 401k

Employer Match — Never Leave Free Money

How Your 401(k) Grows: The Power of Compounding

The reason starting early matters so much is compound growth. Suppose you contribute $500 a month starting at age 30, your employer adds a 50% match on the first 6% of a $60,000 salary, and the account earns an average 7% annual return. By age 65 the balance could exceed $1.3 million — and well over half of that total is investment growth rather than the money you actually contributed. Delaying just ten years, starting at 40 instead of 30, can cut the final balance roughly in half, because the earliest dollars have the longest time to compound.

When Can You Withdraw Your 401(k)?

401(k) vs IRA — Use Both

A 401(k) offers a much higher contribution limit and the valuable employer match, but a limited menu of investment funds. An IRA has a lower contribution limit but lets you invest in almost any stock, bond, or fund. A common strategy is to contribute to your 401(k) up to the full employer match (free money), then fund an IRA for its wider investment choice, and finally return to the 401(k) to use up the remaining limit.

What This Calculator Assumes

Projections assume a constant annual return and steady contributions, compounded over time. Real markets fluctuate year to year, so treat the result as a planning estimate rather than a guarantee. Adjusting the expected return by even one or two percentage points significantly changes the projected balance — try a conservative figure (around 6–7%) for a realistic baseline.

Frequently Asked Questions — 401k Calculator

Written and reviewed by the FreeBytes Editorial Team · Last updated: June 2026