What's the difference between traditional and Roth 401(k)?

Traditional: pre-tax now, taxed in retirement. Roth: post-tax now, tax-free in retirement. Roth tends to win if you expect to be in a higher tax bracket later.

Is 7% a realistic long-term return?

It's slightly below the historical S&P 500 average of ~10% nominal. After expenses and inflation, 6-7% real return is reasonable for diversified equity index funds.

What are the 2026 contribution limits?

Per IRS Notice 2025-67, the 2026 employee elective-deferral limit is $24,500 (up from $23,500 in 2025). Catch-up contributions for age 50+ rise to $8,000 (total $32,500). Under SECURE 2.0, ages 60–63 may use a higher catch-up of $11,250.

When can I access 401(k) money without penalty?

Generally age 59½ for tax-deferred withdrawals without the 10% early-withdrawal additional tax. The "Rule of 55" allows penalty-free withdrawals from your most recent employer's plan if you separate from service in or after the year you turn 55. SEPP/72(t) plans are another exception.

What's the difference between traditional and Roth 401(k)?

Traditional: pre-tax now, taxed in retirement. Roth: post-tax now, tax-free in retirement. Roth tends to win if you expect to be in a higher tax bracket later.

Is 7% a realistic long-term return?

It's slightly below the historical S&P 500 average of ~10% nominal. After expenses and inflation, 6-7% real return is reasonable for diversified equity index funds.

What are the 2026 contribution limits?

Per IRS Notice 2025-67, the 2026 employee elective-deferral limit is $24,500 (up from $23,500 in 2025). Catch-up contributions for age 50+ rise to $8,000 (total $32,500). Under SECURE 2.0, ages 60–63 may use a higher catch-up of $11,250.

When can I access 401(k) money without penalty?

Generally age 59½ for tax-deferred withdrawals without the 10% early-withdrawal additional tax. The "Rule of 55" allows penalty-free withdrawals from your most recent employer's plan if you separate from service in or after the year you turn 55. SEPP/72(t) plans are another exception.

401(k) Calculator

401(k) growth projection with employer match and salary increases.

Result

Balance at retirement (30 yrs)

$1,244,887.42

At retirement

$1220k

You$214,089(18%)

Employer$142,726(12%)

Growth$863,072(71%)

Your total contributions$214,089.37
Employer match contributions$142,726.25
Total contributed (you + employer)$356,815.62
Compounded growth$863,071.80
Final salaryafter 30 yrs of 3% growth$182,044.69
Optimal contribution % (capture full match)Beyond the match, additional contributions still grow tax-deferred but no longer get the 100% match boost. Hit the IRS limit ($24,500 in 2026) before adding to a Roth IRA or taxable brokerage.6% ✓ — capturing the full 4% matchgood

Your projected balance

6% of salary contribution + 4% employer match

$1,244,887.42

Same plan, no employer match

Match adds $416,789.99 (compounded) — capture it first.

$828,097.43

2026 IRS elective-deferral limit

Plus $8,000 catch-up at 50+; $11,250 super-catch-up at 60–63 (SECURE 2.0).

$24,500 (Notice 2025-67)

Source: IRS 401(k) Limits and Notice 2025-67 (2026 figures); SECURE 2.0 Act of 2022 super-catch-up.

Not financial advice — Excludes plan-level fees (0.3–1.5%/yr drag), vesting schedules, RMDs starting at 73 under SECURE 2.0. Constant-return projection ignores sequence-of-returns risk. Not investment or tax advice.

How to use this calculator

Enter your current 401(k) balance and your annual salary.
Set your contribution % (try at least enough to capture the full employer match).
Add the employer match — common: 50% of the first 6% you contribute, so set 3%.
Use 7% return long-term, 3% salary growth.

About this tool

A 401(k) is the most powerful retirement vehicle most workers have access to — pre-tax contributions, tax-deferred growth, and (often) free money from your employer in the form of matching. This calculator models all of it: your contribution percentage, employer match (commonly 50% of your contribution up to 6% of salary), expected investment return, and salary growth over time. Watch what happens when you bump your contribution from 3% to 6% with a 4% match — you're effectively adding 7% of your salary to your future self every year.

How it works — the formula

FV = PMT · ((1+r)^n − 1) / r · (1+r)   plus employer match
Matched dollar = Match% × min(your contribution%, match cap%) × salary

The future value of an annuity-due (contributions at the start of each period) gives the projected balance at retirement under a constant return r and n compounding periods. Employer matches are layered on top per the plan's formula — a typical "100% on first 3%, 50% on next 2%" provides up to a 4% boost on top of your contribution, free money the IRS still treats as elective for vesting purposes.

Sources: IRS — 401(k) limits and the Notice 2025-67 announcement of 2026 figures · SECURE 2.0 Act of 2022 — Sections on age-60–63 super catch-up · Vanguard — How America Saves 2024 (annual benchmarks for participation, contributions, and balances)

Worked examples

Example 1

30-year-old maxing for 35 years

Inputs:: salary = $100k, contribute $24,500/yr (2026 limit), match = $4,000/yr, r = 7%, t = 35y, contributions at year-start
Output:: FV ≈ $4.22M at age 65

Example 2

Mid-career, capturing the match only

Inputs:: salary = $80k, contribute 4% ($3,200/yr) + 4% match, r = 7%, t = 25y
Output:: FV ≈ $433k — captures match but well short of the 4% rule retirement target

Example 3

Late starter, 50+ with catch-up

Inputs:: age = 50, contribute $32,500/yr (2026 with catch-up), r = 6%, t = 17y
Output:: FV ≈ $972k — credible if combined with prior savings and Social Security

Limitations

IRS limits change annually — the 2026 figures cited apply to elective deferrals only; the overall 415(c) limit is $70,000 for 2026.
Vesting schedules can mean some of the employer match is forfeited if you leave before fully vested.
Required Minimum Distributions (RMDs) begin at age 73 under SECURE 2.0 and can force taxable withdrawals against the saver's preference.
Plan-level fees (record-keeping, fund expense ratios) can drag returns by 0.3–1.5%/yr — not modeled here.

401(k) projections rely on current tax law, plan terms, and a constant return assumption. This calculator does not provide tax, retirement, or investment advice — work with a CFP® or tax professional and check the IRS website for the year's definitive limits.

Frequently asked

Minimum: enough to capture the full employer match — that's a guaranteed 100% return. Better: 10-15% of salary including the match. The IRS sets the elective-deferral limit each year (see the editorial section below for current figures).