What is a 401(k) and how does it work?

A 401(k) is an employer-sponsored retirement savings plan allowing pre-tax or Roth contributions that grow tax-deferred. The 2025 contribution limit is $23,500 ($31,000 for those 50+). Many employers match contributions, providing additional free savings.

What is employer match and why does it matter?

Employer matching is when your company adds money to your 401(k) based on your contributions — typically 50-100% of what you contribute up to a percentage of salary. Not contributing enough to capture the full match means leaving free money on the table. Over 30 years at 7%, even $1,800/year in match grows to over $170,000.

How does compound growth work in retirement accounts?

Compound growth means your returns generate their own returns. $10,000 at 7% for 30 years grows to about $76,000 without adding another dollar. Starting even 10 years earlier can more than double your final balance.

How much should I save for retirement?

A common rule is 10-15% of gross income including employer match. The 4% rule suggests you need 25x your desired annual income saved (e.g., $1.5M to withdraw $60,000/year). Fidelity recommends 1x salary saved by 30, 3x by 40, 6x by 50, and 10x by 67.

Retirement Calculator — 401k & Savings Projector | Temporary Email Address generator edu email 2026

What is a Retirement Calculator?

A retirement calculator projects how much money you will have accumulated by the time you stop working, based on your current savings, regular contributions, employer matching, and expected investment returns. It uses the power of compound interest — where investment gains generate their own gains over time — to estimate your retirement nest egg. Even small increases in monthly contributions or a few extra years of saving can dramatically improve your retirement outcome.

Americans rely primarily on workplace plans like the 401(k) or 403(b) for retirement savings. In 2025, the 401(k) contribution limit is $23,500 ($31,000 if you're 50+). Employer matching is effectively free money — most financial advisors recommend contributing at least enough to capture the full match. This calculator models both your contributions and your employer's match growing at your specified annual return rate.

How to Use the Retirement Calculator

Enter your Current Age and Retirement Age (default 65).
Enter your Current Savings — the total already in your 401(k), IRA, or other retirement accounts.
Enter your Monthly Contribution — what you plan to contribute each month going forward.
Set the Expected Annual Return — historically the S&P 500 has averaged ~10% (7% inflation-adjusted). We default to 7%.
Enter your Employer Match — e.g., "50% match on first 6% of pay." Enter your monthly contribution as a dollar amount that reflects your salary percentage.
Results update live — view projected balance, contributions breakdown, and year-by-year table.

Why Use Our Retirement Calculator?

Employer Match Modeled — See the real impact of free matching dollars compounding over decades.
Year-by-Year Table — Watch your balance grow year by year with full transparency.
100% Free & Private — No login required, no data sent to any server.
Instant Live Results — Adjust any input and see the projection update immediately.
Growth Breakdown — Clearly separates your contributions, employer match, and investment growth.

Frequently Asked Questions

A 401(k) is an employer-sponsored retirement savings plan that allows employees to contribute pre-tax dollars (traditional) or after-tax dollars (Roth). Contributions reduce your current taxable income in a traditional 401(k), and investments grow tax-deferred until withdrawal in retirement (at which point they're taxed as ordinary income). In 2025, employees under 50 can contribute up to $23,500; those 50 and older can add a $7,500 catch-up contribution for a total of $31,000. Many employers offer matching contributions as an incentive to participate.

Employer matching is when your company contributes money to your retirement account based on how much you contribute — it's effectively part of your compensation. A common formula is "50% match on the first 6% of salary": if you earn $60,000 and contribute 6% ($3,600/year), your employer adds $1,800. Not contributing enough to get the full match is widely considered the single biggest retirement savings mistake — you're leaving guaranteed 50–100% returns on the table. Over 30 years at 7% growth, $1,800/year in match alone grows to over $170,000.

Compound growth means your investment returns generate their own returns. For example, $10,000 at 7% earns $700 in year 1 ($10,700 total). In year 2, the 7% is applied to $10,700, earning $749. Over 30 years without adding another dollar, $10,000 grows to approximately $76,000. This is the "eighth wonder of the world" — and it explains why starting early is so powerful. Waiting just 10 years to start saving can cost you more than half your final retirement balance, even if you contribute the same total amount.

A common rule of thumb is to save 10–15% of your gross income for retirement, including employer match. Fidelity's milestone guideline suggests having 1× your salary saved by 30, 3× by 40, 6× by 50, 8× by 60, and 10× by 67. The "4% rule" suggests you can safely withdraw 4% of your retirement portfolio annually — so to replace $60,000/year of income, you'd need $1.5 million saved. Social Security will supplement this amount, reducing how much you need to save personally. Use this calculator to see if you're on track and how adjusting contributions affects your outcome.

Quick Facts

✓ 401(k) limit 2025: $23,500 ($31,000 age 50+)
✓ S&P 500 historical avg: ~10% / ~7% inflation-adj
✓ Default return rate: 7% (conservative)
✓ Employer match is free money — always capture it
✓ Your data never leaves your device

Retirement Calculator