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401(k) Calculator

Project 401(k) growth with contributions and optional employer match.

Modify the values and click Calculate to use
e.g. 50 means employer matches 50¢ per $1 you contribute.

Results

Results appear here after you calculate. Numbers use tabular formatting for easy scanning.

How this calculator works

Formulas

Monthly Total

Explanation

Estimates only — not financial, medical, or legal advice. Confirm important decisions with a qualified professional. Methodology · Report an issue

Amortization schedule

Scroll sideways to see every column
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About the 401(k) Calculator

The 401(k) Calculator is a Financial tool on CalculatorNestX built for anyone who needs a clear money estimate before making a budgeting or financing decision.

It focuses on the inputs that matter for this problem — Current age, Age of retirement, Current 401(k) balance ($), Annual salary ($), Your contribution (% of salary), Employer match (%), Employer match limit (% of salary), Expected annual return (%), and Expected annual salary increase (%) — and returns labeled outputs you can check against the formulas on this page.

Results are estimates for planning and learning. They are not a substitute for licensed financial, medical, legal, or engineering advice.

How to use this calculator

Follow these steps on the 401(k) Calculator. Only the fields shown in the form are used — no hidden inputs are required for the published method.

Sample starting values on this page include: Current Age=30, Retirement Age=65, Current Balance=20000, Annual Salary=70000, Contribution Percent=6.

  1. Open the Inputs panel and review each labeled field.
  2. 2. Enter a realistic value for “Current age”.
  3. 3. Enter a realistic value for “Age of retirement”.
  4. 4. Enter a realistic value for “Current 401(k) balance ($)”.
  5. 5. Enter a realistic value for “Annual salary ($)”.
  6. 6. Enter a realistic value for “Your contribution (% of salary)”.
  7. 7. Enter a realistic value for “Employer match (%)”.
  8. 8. Enter a realistic value for “Employer match limit (% of salary)”.
  9. 9. Enter a realistic value for “Expected annual return (%)”.
  10. Select Calculate to refresh the main result, breakdown table, and charts from your current inputs.
  11. Use Example to load a worked sample, or Reset fields to clear the form.
  12. Scroll to the tables and graphs below the result card for the schedule or visual explanation tied to this run.

Formula and calculation method

Money tools on CalculatorNestX use standard time-value relationships (PMT, FV, PV, compounding) unless a page notes a jurisdiction-specific rule.

See assumptions below for scope, units, and limitations that apply to this page.

Formulas

  • Each year: Balance = (Balance + Employee contribution + Employer match) × (1 + Return)
  • Employer match = Salary × min(Your %, Match limit %) × Match rate %

Assumptions

  • Contribution % and salary are applied annually (not per paycheck) for simplicity; IRS contribution limits are not enforced.

Use the CalcAtlas 401K Calculator to explore inputs, view methodology notes, and export results when available.

CalculatorNestX methodology

Worked example

This is an illustrative example only. It is not your live result — your outputs update only after you press Calculate with your own inputs.

Example inputs

  • Current Age: 30
  • Retirement Age: 65
  • Current Balance: 20000
  • Annual Salary: 70000
  • Contribution Percent: 6
  • Employer Match Percent: 50
  • Employer Match Limit Percent: 6
  • Annual Return: 7
  • Salary Increase Percent: 2

Load the sample with Example (or enter the values above), then press Calculate.

After Calculate, compare the payment or balance summary with the amortization or growth table — totals should reconcile within normal rounding.

Understanding your results

On the 401(k) Calculator, the headline result is the primary answer from the engine.

The results table restates the important outputs from this calculation with units and rounding consistent with the main answer.

The chart or diagram visualizes the same numbers as the table — it never invents a separate dataset.

If something looks off, re-check units and required fields, then recalculate. Totals may differ by a few cents due to rounding on long schedules.

Frequently asked questions

It computes the outputs shown in the Results panel from the form fields on this page (including Current age, Age of retirement, Current 401(k) balance ($), Annual salary ($), and Your contribution (% of salary)), then builds a matching breakdown table and chart from that same run.

Each year: Balance = (Balance + Employee contribution + Employer match) × (1 + Return) Employer match = Salary × min(Your %, Match limit %) × Match rate %

Long schedules round each row to cents. Final-payment adjustments and extra payments can shift the last period so the balance reaches zero without changing the published method.

Projections assume a constant rate of return — real markets fluctuate year to year.

Contribution % and salary are applied annually (not per paycheck) for simplicity; IRS contribution limits are not enforced.

If the form has an employer match field, enter the match you expect. Actual plan rules, vesting, and contribution limits vary — this is not tax or retirement advice.