What percentage should I contribute?

At least enough to capture the full employer match (often 5-6% of salary). Targeting 15% of gross income including match is a common long-term goal.

What happens if I change jobs?

You can roll the 401(k) into your new employer’s plan or into an IRA. Rolling into an IRA usually gives more investment options.

What's the 2026 401(k) contribution limit?

Employee deferral: $23,500/year (up from $23,000 in 2024). Catch-up contribution for age 50+: additional $7,500. New SECURE 2.0 super-catch-up for ages 60-63: additional $11,250 (instead of regular $7,500). Total employer + employee combined limit: $70,000 ($77,500 with catch-up). Maxing out the employee contribution at $23,500 takes $1,958/month. Most workers don't max; the median 401(k) contribution is around 7% of salary. Even maxing the employer match (typically 5-6% of salary) is a strong default.

Should I contribute to traditional or Roth 401(k)?

Traditional 401(k): pre-tax contributions, lower current taxable income, taxed when withdrawn in retirement. Best when current tax bracket is HIGHER than expected retirement bracket. Roth 401(k): after-tax contributions, no current tax savings, withdrawals tax-free in retirement. Best when current tax bracket is LOWER than expected retirement bracket. Most early-career workers are in lower tax brackets and benefit from Roth; mid-career high earners in 24-37% brackets benefit from traditional. Mixing both (50/50 split) hedges tax-policy uncertainty. Some employers only offer one option.

What's the employer match worth over a career?

Typical match: 50% of contributions up to 6% of salary. On $100K salary contributing 6%: you contribute $6K, employer adds $3K = $9K/year. Over 30 years at 7% return, employer match alone (the $3K/year) grows to $283K. Combined with employee contributions, the total balance is ~$850K. Skipping the match leaves $283K of free money on the table. Even cash-strapped workers should contribute at least to the match level — it's an instant 50% return that no other investment offers.

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

Age 59.5: penalty-free withdrawals (regular income tax still applies on traditional 401(k); Roth withdrawals tax-free). Age 55 if you separate from employer: 'Rule of 55' allows penalty-free withdrawals from THAT employer's 401(k) only. Hardship withdrawals: medical expenses, first-home purchase, education, eviction prevention — penalties may be waived but income tax still applies. 401(k) loans: borrow up to 50% or $50K from your own 401(k), repay with interest to yourself, must repay within 5 years (immediately if you leave the employer). RMDs (required minimum distributions): start at age 73 (for those born 1951-1959) or 75 (born 1960+).

Is this 401(k) calculator accurate for my employer plan?

The compound-growth math is exact for any employer plan that compounds monthly (almost all do). What varies by plan: (1) Match formula — most plans match 50% up to 6% of salary, but some are 100% up to 3-4%, some require multi-year vesting before match is yours, and some make match in employer stock. (2) Investment options — your plan's fund lineup determines actual return; high-fee target-date funds (1%+ expense) drag final balance by 25-30% vs low-cost index funds (0.05%). (3) After-tax / Roth options — some plans offer Mega Backdoor Roth that lets you contribute up to $70K total ($23,500 traditional + $46,500 after-tax converted to Roth). Read your Summary Plan Description (SPD) to confirm match formula, vesting, and fund lineup before relying on the calculator number.

How do I calculate 401(k) growth manually?

Use the future-value formula: FV = P(1+r)^n + PMT × [((1+r)^n - 1) / r]. P = starting balance, PMT = monthly contribution INCLUDING employer match, r = monthly rate (annual ÷ 12), n = months. Example: $10K starting, $1,200/month ($800 you + $400 match), 7% annual, 30 years. FV = 10000 × (1.00583)^360 + 1200 × [((1.00583)^360 - 1) / 0.00583] ≈ $80K + $1.46M = $1.54M. Excel: =FV(0.07/12, 30*12, -1200, -10000). Important: traditional 401(k) is taxed on withdrawal — multiply by (1 - retirement bracket) for after-tax dollars. At 22% retirement bracket, $1.54M traditional = $1.20M after-tax; Roth 401(k) keeps the full $1.54M.

What's the best 401(k) contribution strategy?

The standard hierarchy: (1) Contribute to employer match — always, no exceptions. Skipping match is leaving free money on the table. (2) Pay off debt above 7% interest before maxing 401(k) — guaranteed 7% beat is rare elsewhere. (3) Max Roth IRA ($7K/year) before maxing 401(k) — Roth has more flexibility, no RMDs, broader fund choice. (4) Max remaining 401(k) ceiling ($23,500 - what you've already contributed for match). (5) HSA if eligible ($4,300 single / $8,550 family) — triple tax benefits make HSA the best account in the US tax code. (6) Taxable brokerage. Allocation rule of thumb: traditional 401(k) for high earners (24%+ federal bracket), Roth for lower brackets, mix for hedging. Always pick low-fee index funds inside the plan.

Money & Finance · Free tool

401(k) Calculator

Project your 401(k) balance at retirement. Includes employer match, contribution increases, and realistic market return assumptions.

Updated June 2026

Starting balance ($)Monthly deposit ($)Annual return (%)Years

Final balance

$1,057,142

You contributed

$298,000

Interest earned

$759,142

Year-by-year growthContributionsInterest

31 rows — one per year plus the starting balance

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What it does

A 401(k) calculator that projects your balance at retirement based on current balance, monthly contributions (including employer match), assumed annual return, and years until retirement. The underlying math is compound interest with periodic contributions.

$800/month ($9,600/year, well under the 2026 limit) at 7% for 30 years = $1.18M. The employer match is the highest-return contribution you’ll ever make — don’t leave it on the table. If your employer matches 50% up to 6% of salary, always contribute at least 6% even if you can’t max out.

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Example input & output

Input

Current balance: $10,000
Monthly contribution (you + match): $800
Annual return: 7%
Years: 30

Output

Projected balance: $1,188,000
Total contributed: $298,000
Growth: $890,000

Growth triples contributions at 30 years — this is the compounding argument in a single number.

How to use it

Enter your current 401(k) balance.
Add your monthly contribution plus employer match.
Use 7% as a reasonable long-term return assumption.
Set years to retirement.
See the projected balance.

How it works

Key takeaways

Employer match is the highest-return investment available — typically a 50-100% return on day one. Skipping it leaves free money on the table.
Standard contribution priority: match → high-interest debt → Roth IRA → HSA → max 401k → taxable brokerage.
A 1% expense ratio compounds to 25-30% of total return over 30 years. Switch to low-cost index funds (0.03-0.10% expense) inside your 401k whenever available.
Vesting schedules matter: leaving your job before fully vested forfeits the unvested employer match. Cliff vs graded varies by plan — check your SPD.

Same compound-interest math as any retirement calculator: FV = P(1+r)^n + PMT × [((1+r)^n - 1) / r]. The 401k twist: contribution is pre-tax (lowering current-year taxable income) and grows tax-deferred. Withdrawals in retirement are taxed as ordinary income.

Advanced: contribution priority + tax mechanics

The standard contribution-priority order: (1) 401k up to employer match (highest single-period return any investment offers — typically 50-100% on day one). (2) High-interest debt (credit cards over 18%). (3) Roth IRA full ($7K/year). (4) HSA if eligible ($4,300 single / $8,550 family for 2025). (5) 401k remaining ceiling ($23,500 total - what you’ve already contributed). (6) Taxable brokerage. The tax mechanic that’s most often missed: traditional 401k contributions reduce your AGI, which can keep you eligible for Roth IRA, child tax credits, ACA subsidies, and student-loan interest deduction. A high-bracket worker hovering near the Roth phase-out can use traditional 401k contributions to drop AGI under the limit and contribute to BOTH 401k and Roth IRA. See the Roth IRA calculator and 401k contribution-limit glossary.

How this compares to alternatives

vs Vanguard / Fidelity 401k tools: those use their own fund-mix assumptions and may bake in expense ratios; ours forces explicit return rate so you control the assumption. vs paychecks-into-investing-rate spreadsheet: spreadsheet allows custom modeling (changing contribution mid-career, accounting for raises) but takes time to build. vs theretirement calculator: retirement calculator focuses on multi-account distribution and withdrawal phase; this 401k calculator focuses on accumulation only.

Common mistakes when using this tool

Forgetting employer match in “monthly contribution”. If you contribute $500 and employer matches $250, enter $750 (combined). Skipping the match input under-projects the actual balance.
Optimistic return assumptions. 10% nominal looks great but ignores inflation; 7% real (inflation-adjusted) is the conservative default. The result then approximates today’s purchasing power.
Ignoring vesting schedules. Employer match often vests over 3-6 years (cliff or graded). Leaving job before fully vested forfeits unvested match. Check your plan documents.
Not increasing with raises. Most plans let you set a percentage, not a dollar amount; raises automatically increase contribution. Some plans require manual adjustment after each raise — check yours, set a calendar reminder.
Overlooking high-fee target-date funds. Default 401k funds often have 0.5-1.5% expense ratios. Over 30 years that costs 25-30% of total return. Check your plan’s lineup for low-cost index funds (0.03-0.10% expense ratios) and switch.

Learn more about 401(k) plans

Employer match explained — how different match structures work, why match is the highest-return investment available.
401(k) vesting schedules — cliff vs graded vesting, what happens when you leave before fully vested.
Required Minimum Distributions — the SECURE 2.0 rules, the 25% penalty for missing one, and Roth-conversion strategies to reduce them.
Compound interest glossary — the engine behind 30 years of tax-deferred growth.

When to use this tool

Annual retirement planning review.
Deciding whether to increase your contribution percentage.
Comparing the long-term effect of different employer match levels.

When not to use it

Calculating Roth conversions or RMD strategy — different math.
Tracking asset allocation or rebalancing (use a brokerage tool).

Common use cases

Projecting your retirement balance.
Seeing the impact of increasing contributions by 1% of salary.
Modeling a catch-up contribution strategy close to retirement.

Frequently asked questions

What percentage should I contribute?: At least enough to capture the full employer match (often 5-6% of salary). Targeting 15% of gross income including match is a common long-term goal.
What happens if I change jobs?: You can roll the 401(k) into your new employer’s plan or into an IRA. Rolling into an IRA usually gives more investment options.
What's the 2026 401(k) contribution limit?: Employee deferral: $23,500/year (up from $23,000 in 2024). Catch-up contribution for age 50+: additional $7,500. New SECURE 2.0 super-catch-up for ages 60-63: additional $11,250 (instead of regular $7,500). Total employer + employee combined limit: $70,000 ($77,500 with catch-up). Maxing out the employee contribution at $23,500 takes $1,958/month. Most workers don't max; the median 401(k) contribution is around 7% of salary. Even maxing the employer match (typically 5-6% of salary) is a strong default.
Should I contribute to traditional or Roth 401(k)?: Traditional 401(k): pre-tax contributions, lower current taxable income, taxed when withdrawn in retirement. Best when current tax bracket is HIGHER than expected retirement bracket. Roth 401(k): after-tax contributions, no current tax savings, withdrawals tax-free in retirement. Best when current tax bracket is LOWER than expected retirement bracket. Most early-career workers are in lower tax brackets and benefit from Roth; mid-career high earners in 24-37% brackets benefit from traditional. Mixing both (50/50 split) hedges tax-policy uncertainty. Some employers only offer one option.
What's the employer match worth over a career?: Typical match: 50% of contributions up to 6% of salary. On $100K salary contributing 6%: you contribute $6K, employer adds $3K = $9K/year. Over 30 years at 7% return, employer match alone (the $3K/year) grows to $283K. Combined with employee contributions, the total balance is ~$850K. Skipping the match leaves $283K of free money on the table. Even cash-strapped workers should contribute at least to the match level — it's an instant 50% return that no other investment offers.
When can I withdraw 401(k) money without penalty?: Age 59.5: penalty-free withdrawals (regular income tax still applies on traditional 401(k); Roth withdrawals tax-free). Age 55 if you separate from employer: 'Rule of 55' allows penalty-free withdrawals from THAT employer's 401(k) only. Hardship withdrawals: medical expenses, first-home purchase, education, eviction prevention — penalties may be waived but income tax still applies. 401(k) loans: borrow up to 50% or $50K from your own 401(k), repay with interest to yourself, must repay within 5 years (immediately if you leave the employer). RMDs (required minimum distributions): start at age 73 (for those born 1951-1959) or 75 (born 1960+).
Is this 401(k) calculator accurate for my employer plan?: The compound-growth math is exact for any employer plan that compounds monthly (almost all do). What varies by plan: (1) Match formula — most plans match 50% up to 6% of salary, but some are 100% up to 3-4%, some require multi-year vesting before match is yours, and some make match in employer stock. (2) Investment options — your plan's fund lineup determines actual return; high-fee target-date funds (1%+ expense) drag final balance by 25-30% vs low-cost index funds (0.05%). (3) After-tax / Roth options — some plans offer Mega Backdoor Roth that lets you contribute up to $70K total ($23,500 traditional + $46,500 after-tax converted to Roth). Read your Summary Plan Description (SPD) to confirm match formula, vesting, and fund lineup before relying on the calculator number.
How do I calculate 401(k) growth manually?: Use the future-value formula: FV = P(1+r)^n + PMT × [((1+r)^n - 1) / r]. P = starting balance, PMT = monthly contribution INCLUDING employer match, r = monthly rate (annual ÷ 12), n = months. Example: $10K starting, $1,200/month ($800 you + $400 match), 7% annual, 30 years. FV = 10000 × (1.00583)^360 + 1200 × [((1.00583)^360 - 1) / 0.00583] ≈ $80K + $1.46M = $1.54M. Excel: =FV(0.07/12, 30*12, -1200, -10000). Important: traditional 401(k) is taxed on withdrawal — multiply by (1 - retirement bracket) for after-tax dollars. At 22% retirement bracket, $1.54M traditional = $1.20M after-tax; Roth 401(k) keeps the full $1.54M.
What's the best 401(k) contribution strategy?: The standard hierarchy: (1) Contribute to employer match — always, no exceptions. Skipping match is leaving free money on the table. (2) Pay off debt above 7% interest before maxing 401(k) — guaranteed 7% beat is rare elsewhere. (3) Max Roth IRA ($7K/year) before maxing 401(k) — Roth has more flexibility, no RMDs, broader fund choice. (4) Max remaining 401(k) ceiling ($23,500 - what you've already contributed for match). (5) HSA if eligible ($4,300 single / $8,550 family) — triple tax benefits make HSA the best account in the US tax code. (6) Taxable brokerage. Allocation rule of thumb: traditional 401(k) for high earners (24%+ federal bracket), Roth for lower brackets, mix for hedging. Always pick low-fee index funds inside the plan.

See how this compares

Head-to-head401(k) vs Roth IRA401(k) vs Roth IRA head-to-head: employer match, contribution limits, tax treatment, and the exact order to fund them. Free projection tools included.

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