onlinecalculator.me

Free online 401(k) retirement calculator

A 401(k) is a workplace retirement account funded with pre-tax dollars that grow tax-deferred. This calculator projects your balance at retirement, accounting for employer.

About this calculator

How to use

  1. Enter your current age and the age at which you plan to retire.
  2. Enter your current 401(k) balance and annual contribution amount.
  3. Set the employer match percentage (e.g., 100 means your employer matches dollar-for-dollar).
  4. Adjust the annual return and inflation rate.
  5. Click Calculate 401(k) to see your projected balance and the year-by-year table.

The formula

Each year’s balance is calculated as:

balance = (prev_balance + contribution + employer_match) × (1 + return_rate)

The inflation-adjusted (real) balance is:

balance_real = balance / (1 + inflation_rate)^years

Worked example

Age 30, retiring at 65 (35 years). Current balance: $50,000. Annual contribution: $19,500. Employer match: 100%. Annual return: 7%. Inflation: 2.5%.

  • Employer adds $19,500/year for 35 years = $682,500 in match (before growth)
  • Projected nominal balance at 65: approximately $7.4 million
  • In today’s dollars (inflation-adjusted): approximately $3.0 million

The projection illustrates the compounding power of tax-deferred growth and employer match over a long career.

Notes

  • This calculator does not model IRS contribution limits, which change annually.
  • Withdrawals from traditional 401(k) plans are taxed as ordinary income at retirement. The Roth 401(k) variant allows tax-free withdrawals.
  • The 7% return assumption is nominal, not real. If you compare to inflation-adjusted figures, subtract the inflation rate to get the real return.

Frequently asked

What is employer match and how does it work?
Many employers match a percentage of what you contribute — for example, 100% match up to the IRS limit means for every dollar you put in, your employer adds another dollar. This calculator uses the match as a percentage of your annual contribution. A 50% match on $10,000 means your employer adds $5,000.
What annual return should I use?
A 7% nominal return is commonly cited as a long-run historical average for a diversified US stock portfolio. You can adjust it to reflect a more conservative allocation (bonds, target-date funds) or a higher-growth scenario. Past returns do not guarantee future results.
How does inflation affect my 401(k)?
The calculator shows two balances — the projected nominal balance and the same balance in today's purchasing power. At 2.5% inflation over 35 years, $1 million in the future is worth roughly $420,000 today. Plan for the real, inflation-adjusted figure.
What is the 2026 401(k) contribution limit?
For 2026, the IRS elective deferral limit is $23,500 for employees under 50. Those aged 50 and older can contribute an additional $7,500 catch-up. Employer match does not count toward this limit.