How it works

A useful distinction

Read matching percentages in layers

A 50% employer match on your first 6% of salary contributes at most 3% of salary. Enter the employee threshold and matching rate separately; treating both as 6% overstates the projection.

Reviewing contributions, matching, and withdrawals

A 401(k) projection can separate your contributions from employer matching and investment growth. Review the salary and matching inputs before interpreting the ending balance. Withdrawal modes answer different questions from accumulation and include only the supported tax assumptions. A regional display preference does not change this tool's US account rules, and the projection does not verify the terms of your employer's plan.

Account growth: formula and assumptions

Grow the existing balance and annual end-of-year employee and employer contributions.

Contributions are scenario inputs. This mode does not establish eligibility, apply every statutory limit, or model investment fees.

Early withdrawal estimate: formula and assumptions

Net proceeds = gross withdrawal×(1−tax rate−penalty rate).

Exceptions and tax treatment depend on age, account type, contribution basis, and qualifying circumstances. Enter the applicable rates.

Salary-based contributions & matching: formula and assumptions

Annual balance = opening balance × (1+return) + employee deferral + employer match.

Each matching tier covers a slice up to a cumulative threshold. Contributions occur at year end. The optional 2026 cap uses age-specific catch-up amounts and a frozen compensation/additions limit.

Dated traditional-account distribution: formula and assumptions

Additional tax = 10% × taxable amount not covered by an applicable exception.

Uses exact age 59½ and the qualified-plan separation-year age-55 rule. IRA separation does not qualify. Taxable basis and other exception eligibility are user-supplied assumptions; income tax is separate.

Worked example

Reference example currency: USD. These fixed examples do not change with your calculator preferences.

Using the Account growth example:

Inputs

Current balance ($): 50000
Annual employee contribution ($): 10000
Annual employer contribution ($): 3000
Annual effective return (%): 5
Years: 20
Tax rate on retirement withdrawals (%): 20

Method

Grow the existing balance and annual end-of-year employee and employer contributions.

Result

Example result

Projected account balance: $562,522.29

Illustrative after-tax balance: $450,017.83

Total contributions: $310,000.00

These are illustrative inputs. Change the values to explore a different scenario.

What to keep in mind

Optional contribution caps use frozen 2026 parameters; employer-plan eligibility and future limits need separate checks. The dated traditional-account distribution mode applies only the selected age or verified-exception assumptions.

Formula references

References explain the underlying methods; they do not imply endorsement or individual professional review of Finflo.

Common questions

Are contribution limits always applied to the projection?

No. The salary-based mode offers uncapped scenarios or frozen 2026 limits. Future limits and plan eligibility are not predicted.

How are employer matching tiers applied?

Each tier matches the employee contribution slice up to its cumulative salary threshold. Contributions and the match enter at year end.

How does the dated distribution mode handle the additional tax?

It tests age 59½, the specified employer-plan separation-year rule and entered verified exceptions against the taxable portion. An exception to additional tax does not remove ordinary income tax.

Prepared by Finflo. See our methodology and editorial policy. Read the relevant professional-advice limitations.

401K Calculator

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