Free calculators
Compound Interest Calculator
See how your savings and monthly contributions can grow over time, in today's dollars too.
Results
Compounded monthly, contributions at the end of each month. Returns are not guaranteed.
Want the full version? Net Worth and Savings Goals Tracker
Excel and Google Sheets · instant download · $12
How compound interest works
Compounding means your returns start earning returns of their own. In the early years most of the balance is money you put in. Over time the growth line pulls away from the contribution line, which is why starting early and staying consistent matter more than picking the perfect year to start.
Pick a realistic return
Nobody knows future returns. Many people test a few rates, for example 4%, 6% and 8%, to see a range. Savings accounts and CDs pay less but are steadier; diversified stock funds have historically returned more over long periods, with large swings along the way.
Why inflation matters
A dollar in 25 years buys less than a dollar today. The "in today's dollars" result shows the future value adjusted for the inflation rate you enter, which is a better way to judge whether a goal is on track.
Tracking your progress? The Net Worth and Savings Goals Tracker shows every account, your net worth trend and how much to save each month for up to 15 goals.
Read the guide: How much to save a month to reach $100k, $500k or $1M
Questions
What return should I use?
There is no correct number. Try a conservative, a middle and an optimistic rate to see a range of outcomes rather than a single promise.
Is the result guaranteed?
No. Returns vary from year to year and can be negative. The calculator shows what happens if the average return you enter holds for the whole period.
Does this include taxes or fees?
No. Taxes and fund fees lower real results. If you pay a 1% fee, try lowering the return by 1% to see the effect.
Is this investment advice?
No. It is an educational tool and does not recommend any product or strategy.