Saving & investing
Retirement Calculator
Built and maintained by Chandranshu Kumar · Figures from the IRS, SSA, BLS and Freddie Mac
Take the match, then let time work
If your job matches your 401(k), that match is an immediate return on your own contribution, and turning it down is leaving pay on the table. So the first rule is simple: put in at least enough to get the whole match. After that, the biggest lever is time, not the amount. The same $500 a month started ten years earlier ends up far larger, because those early contributions compound the longest. The growth line in the breakdown usually ends up bigger than everything you and your employer put in combined.
Assumes a steady 7% average return and monthly compounding. Real returns swing year to year. Not financial advice.
How the retirement balance is worked out
The projection starts with what you have saved, $25,000 in this example. Each month the balance grows by the assumed yearly return divided by twelve, then your $500 contribution and the $250 employer match are added on top. Repeating that step for 30 years, or 360 months, is what compound growth looks like in practice.
Over those years you put in $180,000 of your own money and the employer adds $90,000. The balance lands near $1,117,891, so $822,891 of the total is growth rather than money either of you paid in. That growth line usually ends up larger than the contributions once the timeline is long.
The 7% return here is an assumption, not a promise. Real markets rise and fall year to year, and a long run of weak returns would land you below this figure. Treat the result as a planning estimate, and see the full method for the assumptions behind it.
Common questions
Should I always get the full employer match?
Almost always. The match is free money and an instant return on your contribution, so getting the full match usually comes before other savings goals.
Why does starting earlier matter so much?
Because the earliest contributions compound the longest. The same $500 a month begun ten years sooner ends up far larger, since each of those early dollars has an extra decade to earn returns on top of returns. Time in the market tends to matter more than the size of each deposit.
How is this different from a plain compound interest projection?
This version adds the employer match as its own line, since that money is not something you contribute. To model any balance and contribution without a match, the compound interest calculator shows the same growth math on a single stream of savings.