Retirement / 401K Calculator

What this retirement calculator does

It projects the balance of a workplace retirement account at the point you stop working, combining what you have saved already, what you and your employer add each year, and investment growth on the whole amount. Retirement saving is the clearest example of compounding doing the heavy lifting: contributions made in your twenties typically contribute more to the final balance than much larger contributions made in your fifties.

The formula behind it

Your annual contribution is salary × your percentage, and the employer match adds salary × match percentage. The existing balance compounds as B × (1 + r)ⁿ while the annual contributions accumulate as C × [((1 + r)ⁿ − 1) ÷ r]. On a salary of 60,000 with 6% contributed and a 3% match, 5,400 goes in each year — and over 30 years at 7% that becomes roughly 510,000.

How to use this calculator

Enter your current balance, annual salary, your contribution percentage, the employer match, your expected annual return and the years remaining until retirement. The result shows the projected balance at retirement. Increase the contribution by one percentage point and re-run it: the difference over decades is usually larger than people expect.

Getting the most from the account

Contribute at least enough to capture the full employer match — declining it is turning down pay. Raise your contribution alongside each salary increase, so the extra saving never reduces your take-home. Keep fund charges low, since a percentage point of fees compounds against you exactly as returns compound for you. The projection assumes steady contributions and a constant return; treat it as a planning guide and revisit it every few years.