Worked example
Start with $500 a month, raise it by 3% every year, and invest for 25 years at an assumed 7% a year. The estimated value is $535,208, from $218,756 put in.
- Monthly investment
- $500
- Yearly step-up
- 3%
- Assumed return (per year)
- 7%
- Time period
- 25 years
- Amount invested
- $218,756
- Estimated value
- $535,208
| Year | Monthly amount | Invested so far | Estimated value |
|---|---|---|---|
| 1 | $500 | $6,000 | $6,232 |
| 2 | $515 | $12,180 | $13,102 |
| 3 | $530 | $18,545 | $20,662 |
| 4 | $546 | $25,102 | $28,966 |
| 5 | $563 | $31,855 | $38,074 |
| 10 | $652 | $68,783 | $98,113 |
| 15 | $756 | $111,593 | $190,256 |
| 20 | $877 | $161,222 | $329,030 |
| 25 | $1,016 | $218,756 | $535,208 |
How to use this calculator
- Enter your starting monthly contribution.
- Choose how much it rises each year — a percentage or a dollar amount.
- Enter the annual return you expect and how many years you’ll invest.
- Open the Compare view to see the rising plan against a flat one.
Frequently asked questions
Why increase contributions every year?
Because your pay usually rises, and investing a fixed slice of each raise adds up. Starting at $500 a month and raising it 3% a year at 7% for 25 years grows to about $535,208, versus $407,399 if you never raised it.
How much do a couple of extra points of increase matter?
Raising contributions 5% a year instead of 3% takes the projected balance to about $654,016.
Can I increase by a dollar amount instead of a percentage?
Yes — switch the increase type to $ and enter the amount added to your monthly contribution each year.
Does this include employer matching or taxes?
No. It shows your own contributions growing at a steady return, before taxes and fees. A dedicated 401(k) calculator with employer match is on the way.