How accurate is a 401k calculator?

Accurate for the inputs you provide. The biggest uncertainty is the return rate assumption. At 7%, projections are based on conservative long-term stock market expectations. The actual outcome will vary year-to-year but tends to converge toward the projection over 20+ year periods.

What return rate should I use in a 401k calculator?

7% for a diversified balanced portfolio (60–70% stocks, 30–40% bonds). 8% for an equity-heavy portfolio (80–90% stocks). 5–6% for a conservative portfolio. In your 20s and 30s, 7–8% is appropriate. In your 50s approaching retirement, model 5–6% to account for increasing fixed income allocation.

Should I include employer match in the 401k calculator?

Yes, always. Employer contributions are part of your total retirement savings and compound the same as your own contributions. On a $70,000 salary with a 3% match, your employer adds $2,100/year. Over 30 years at 7%, that employer match alone grows to approximately $222,000.

What is the 401k contribution limit for 2025?

Employee contributions are capped at $23,500 in 2025. Those 50 and older can add a $7,500 catch-up contribution for a total of $31,000. The combined limit (employee + employer) is $69,000 or 100% of compensation, whichever is less.

How do I know if I’m on track for retirement with my 401k?

Fidelity’s benchmark: 1x your salary saved by 30, 3x by 40, 6x by 50, 8x by 60, 10x by 67. A quick calculation: if retirement spending will be $60,000/year, you need $1.5 million at a 4% withdrawal rate. Run the calculator to see if your current trajectory reaches that goal.

How to Use the 401k Calculator: Complete Beginner Guide

Most people contribute to their 401k without ever actually running the numbers on what they’ll have at retirement. The 401k calculator closes that gap in about 5 minutes. Here’s how to use it correctly, what each input means, and the three scenarios every participant should run.

What the 401k Calculator Inputs Mean

401k calculator inputs and how to find the values for each

Input	What It Does	Where to Find It
Current Balance	Your starting point — existing 401k savings	Your plan portal or statement
Annual Salary	Used to calculate contribution amounts	Your pay stub
Contribution Rate	% of salary you contribute each paycheck	HR/benefits portal
Employer Match	Free money from your employer up to a % of salary	Offer letter or benefits summary
Annual Return	Expected portfolio growth rate	Use 7% for balanced, 8% for equity-heavy
Years Until Retirement	Time horizon for compounding	Your target retirement age minus current age
Annual Raise	Expected salary increases	Use 2–3% for general estimate

How to Read the Outputs

The calculator projects your balance at retirement. More importantly, it shows how much of that balance came from your contributions, your employer’s contributions, and investment growth. After 30+ years, investment growth typically exceeds contributions by 3–4 times.

📈Where Retirement Wealth Actually Comes From

On a $70,000 salary with 15% contribution and 3% employer match over 30 years at 7% return: you contribute $315,000, your employer adds $63,000, and investment growth generates approximately $855,000. Total: $1.23 million. 70% came from compounding.

Step-by-Step: Running Your First Real Scenario

Log into your 401k provider portal (Fidelity, Vanguard, Empower, etc.) and find your current balance
Enter your current salary and your current contribution percentage
Enter your employer match (typically '3% on first 6% contributed' = add 3% employer)
Set return rate to 7% (conservative balanced portfolio assumption)
Set years to retirement based on your target age
Note the projected balance and whether it meets your retirement income goal
Run it again at 10% contribution vs. 15% to see the difference

30-year 401k projections at different contribution rates — $70,000 salary, age 30 start

Scenario	Your Contribution	Employer Match	Rate	30-Year Projection ($70K salary)
Bare minimum (match only)	3%	1.5%	7%	$426,000
Modest saver	6%	3%	7%	$852,000
Good saver	10%	3%	7%	$1,278,000
Aggressive saver	15%	3%	7%	$1,746,000
Max contribution	$23,500/yr	3%	7%	$2,368,000

Three Scenarios Everyone Should Run

Current path: What your balance looks like if nothing changes
+3% contribution increase: How much more raising your rate by 3% generates
Maximum contribution: What maxing the $23,500 limit builds to — often surprisingly achievable with planning

Run Your 401k Retirement Projection

Enter your salary, contribution rate, and years to retirement — see exactly what your 401k will be worth.

Open 401(k) Calculator →