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Saving years

How much could my 401(k) or investment grow?

Isolate one account during the saving years: your contributions, the employer’s, and investment growth, with fees and inflation made visible.

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Last reviewed: September 4, 2026 · model build 20260906-05 · 2026 federal parameters

On this page

  1. What this calculator answers
  2. Worked example
  3. 2026 contribution limits
  4. How the calculation works
  5. Limitations
  6. Frequently asked questions
What this calculator answers

Given a current balance, your monthly contribution, an employer contribution, an expected total return, a fee, and a number of years, it shows the projected balance and separates money you put in from market growth. It flags contributions above the 2026 employee deferral limit.

Worked example

$100,000 today, $1,000 a month from you and $500 from an employer (rising 2% a year), 7% return, 0.25% fee, 25 years: about $1.87 million, of which about $577,000 is contributions and $1.20 million is growth. In today’s dollars at 2.5% inflation, about $1.01 million.

2026 contribution limits
Account2026 limit
401(k), 403(b), 457(b), TSP employee deferral$24,500
Catch-up, age 50 and older$8,000
Catch-up, ages 60–63$11,250
Total employee + employer (415(c))$72,000
Traditional and Roth IRA$7,500 (+$1,100 catch-up at 50+)
HSA$4,400 self-only, $8,750 family (+$1,000 at 55+)
SIMPLE IRA$17,000 (+$4,000 catch-up)

Source: IRS Notice 2025-67. Employer contributions do not count toward the employee deferral limit. Beginning in 2026, catch-up contributions for employees who earned more than $150,000 in the prior year must be Roth.

How the calculation works

Contributions are added monthly and earn the net monthly return after fees. Employer contributions are added at the same time. Returns should be total returns; do not add dividends separately. The fee-drag figure compares the result against the same plan with no fee.

Limitations

Steady return only; no taxes on withdrawal; no vesting schedules; no employer match formulas beyond a fixed monthly amount.

Confirm any decision with an official Social Security statement, your plan custodian, and a qualified adviser. See the methodology and changelog for every rule the model applies.

Frequently asked questions

How much can I put in a 401(k) in 2026?

The employee deferral limit is $24,500. People 50 and older can add $8,000; people aged 60 to 63 can add $11,250 instead if the plan allows.

Does the employer match count against my limit?

No. Employer contributions count only toward the overall $72,000 limit on combined contributions.

What return should I use?

A long-run nominal total return of 6–8% for a diversified stock-heavy portfolio is a common planning range; subtract your fund fees separately.

Educational planning tool. Results are estimates, not financial, tax, legal, actuarial, or Social Security advice. Verify claiming choices with an official SSA estimate and qualified advisers.

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