What percentage should I contribute?

At least enough to capture the full employer match (often 5-6% of salary). Targeting 15% of gross income including match is a common long-term goal.

What happens if I change jobs?

You can roll the 401(k) into your new employer’s plan or into an IRA. Rolling into an IRA usually gives more investment options.

Money & Finance · Free tool

401(k) Calculator

Project your 401(k) balance at retirement. Includes employer match, contribution increases, and realistic market return assumptions.

Updated April 2026

Starting balance ($)Monthly deposit ($)Annual return (%)Years

Final balance

$1,057,142

You contributed

$298,000

Interest earned

$759,142

What it does

A 401(k) calculator that projects your balance at retirement based on current balance, monthly contributions (including employer match), assumed annual return, and years until retirement. The underlying math is compound interest with periodic contributions.

$800/month ($9,600/year, well under the 2026 limit) at 7% for 30 years = $1.18M. The employer match is the highest-return contribution you’ll ever make — don’t leave it on the table. If your employer matches 50% up to 6% of salary, always contribute at least 6% even if you can’t max out.

Example input & output

Input

Current balance: $10,000
Monthly contribution (you + match): $800
Annual return: 7%
Years: 30

Output

Projected balance: $1,188,000
Total contributed: $298,000
Growth: $890,000

Growth triples contributions at 30 years — this is the compounding argument in a single number.

How to use it

Enter your current 401(k) balance.
Add your monthly contribution plus employer match.
Use 7% as a reasonable long-term return assumption.
Set years to retirement.
See the projected balance.

When to use this tool

Annual retirement planning review.
Deciding whether to increase your contribution percentage.
Comparing the long-term effect of different employer match levels.

When not to use it

Calculating Roth conversions or RMD strategy — different math.
Tracking asset allocation or rebalancing (use a brokerage tool).

Common use cases

Projecting your retirement balance.
Seeing the impact of increasing contributions by 1% of salary.
Modeling a catch-up contribution strategy close to retirement.

Frequently asked questions

What percentage should I contribute?: At least enough to capture the full employer match (often 5-6% of salary). Targeting 15% of gross income including match is a common long-term goal.
What happens if I change jobs?: You can roll the 401(k) into your new employer’s plan or into an IRA. Rolling into an IRA usually gives more investment options.