401(k) Calculator
A 401(k) calculator projects retirement-plan savings from an existing balance, employee contributions, an employer match, and an assumed investment return. It does not determine plan eligibility, vesting, taxes, fees, or the legally permitted contribution amount.
Quick answer
Employer matching can materially increase contributions. The projection assumes a constant salary and return unless you change the inputs, so it should be treated as a scenario rather than a forecast.
Calculator
How to use this calculator
- Enter the current 401(k) balance and salary.
- Enter employee contribution and estimated employer match.
- Enter an assumed return and years remaining.
- Compare the result with lower-return and contribution scenarios.
Explanation
What it is
A 401(k) calculator projects retirement-plan savings from an existing balance, employee contributions, an employer match, and an assumed investment return. It does not determine plan eligibility, vesting, taxes, fees, or the legally permitted contribution amount.
How it works
The calculator converts annual salary contribution percentages to monthly deposits and compounds them with the current balance at the assumed monthly return.
When to use it
Use the 401(k) calculator when comparing options, setting a realistic target, or checking whether a proposed financial decision fits your broader plan.
Limitations
- The result is an estimate based on the amounts, rates, timing, and assumptions entered.
- Actual product terms, taxes, fees, eligibility rules, and market conditions can change the outcome.
- Use official disclosures or a qualified professional before making a binding financial decision.
Key terms
- 401(k)
- An employer-sponsored defined-contribution retirement plan.
- Employer match
- An employer contribution based on plan rules and employee participation.
- Vesting
- The schedule for gaining ownership of employer contributions.
- Contribution limit
- The annual legal limit, which depends on year, age, contribution type, and plan rules.
Formula
The calculator converts annual salary contribution percentages to monthly deposits and compounds them with the current balance at the assumed monthly return.
Worked example
On a $90,000 salary, a 10% employee contribution plus a 4% employer contribution adds $12,600 a year before investment growth.
FAQ
How much should I contribute to my 401(k)?
At minimum, many workers consider contributing enough to receive the full available match, then balance retirement goals with debt, emergency savings, and cash flow.
Does this enforce the 2026 contribution limit?
No. It projects from the percentage entered. Check current IRS limits and your plan rules, especially for catch-up and after-tax contributions.
Is an employer match guaranteed?
No. Match formulas, eligibility, vesting, and discretionary contributions vary by plan and employer.
What return should I assume?
Use a range that reflects asset allocation, fees, inflation, and uncertainty rather than relying on one optimistic number.
Is a 401(k) balance taxable?
Traditional and Roth contributions have different tax treatment. This calculator shows a nominal account value before withdrawal taxes.
Common mistakes
- Using an advertised rate without checking whether it applies to the full balance or term.
- Leaving out fees, taxes, timing differences, or irregular cash flows.
- Treating a planning estimate as a guaranteed quote or final professional calculation.
Tips
- Run a conservative scenario as well as an optimistic one.
- Change one assumption at a time so you can see what drives the result.
- Save or export the calculation and update it when rates, costs, or goals change.
Sources and editorial review
Educational estimates only; not personalized financial, tax, legal, lending, investment, or insurance advice.