401k Growth Calculator

Work out 401k growth instantly with clear inputs, formula shown and shareable results.

About 401k Growth Calculator

A workplace retirement account grows from two sources: the existing balance compounding and each year's new contribution compounding for the years remaining. Over a long career investment growth usually dwarfs the contributions.

Formula

Account projection

FV = B(1+r)^n + C × [((1+r)^n - 1)/r] × (1+r)

Worked example

With the default values below, 401k Growth Calculator returns Projected Balance At Retirement of $37,383,274.94. Change any input above and every figure here is recalculated in your browser.

Inputs used

Current Balanceminimum 0: 2,000,000
Annual Contributionminimum 0: 300,000
Expected Annual Returnaccepts 0–100 %: 8 %
Years To Retirementaccepts 1–45: 25

Results

Projected Balance At Retirement: $37,383,274.94
Growth Of Today's Balance: $13,696,950.39
Future Contributions: $7,500,000.00
Investment Growth: $27,883,274.94

Step by step

1Values used
2Account projection
3Projected Balance At Retirement= 37,383,274.94
4Growth Of Today's Balance= 13,696,950.39
5Future Contributions= 7,500,000.00
6Investment Growth= 27,883,274.94

Assumptions and limits

The result is derived only from the 4 inputs listed above. Anything not among them is not part of the calculation.
In particular, this calculator does not take inflation, tax or fees or charges into account.
Figures are rounded for display to 2 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.
Figures are estimates for planning only. Market returns are not guaranteed, and rates, limits and tax rules change. This is not financial or tax advice — speak to a qualified adviser before acting.
This is an estimate for general information and not professional financial, tax or legal advice. See the full disclaimer for the limits that apply to this kind of calculator.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

Figures are estimates for planning only. Market returns are not guaranteed, and rates, limits and tax rules change. This is not financial or tax advice — speak to a qualified adviser before acting.

Frequently Asked Questions

Should contributions rise with pay?

Yes if possible — contribution limits are usually indexed, and a rising contribution keeps the plan on track in real terms.

What return should be assumed?

Use a conservative long-run figure net of fund fees, and re-test the plan at a lower rate.