Compound Interest Calculator
Project how your savings grow over time with compound interest
Advanced options
$1,647.01
Final balance
$1,000.00
Total contributed
$647.01
Total interest
Growth over time
Year-by-year schedule
| Year | Balance | Contributed | Interest |
|---|---|---|---|
| 1 | $1,051.16 | $1,000.00 | $51.16 |
| 2 | $1,104.94 | $1,000.00 | $104.94 |
| 3 | $1,161.47 | $1,000.00 | $161.47 |
| 4 | $1,220.90 | $1,000.00 | $220.90 |
| 5 | $1,283.36 | $1,000.00 | $283.36 |
| 6 | $1,349.02 | $1,000.00 | $349.02 |
| 7 | $1,418.04 | $1,000.00 | $418.04 |
| 8 | $1,490.59 | $1,000.00 | $490.59 |
| 9 | $1,566.85 | $1,000.00 | $566.85 |
| 10 | $1,647.01 | $1,000.00 | $647.01 |
Live Results
See your projected balance update instantly as you type
Step-Up Contributions
Model contributions that grow a fixed percentage every year
Growth Chart & Real Value
Visualize balance vs. contributions and see the inflation-adjusted value
Frequently asked questions
How does compounding frequency affect my final balance?
More frequent compounding (daily vs. annually) means interest is calculated and added to your balance more often, so you earn a small amount of interest on interest sooner. The effect is usually modest compared to changes in rate or time, but it does add up over long periods.
How are monthly contributions factored into the calculation?
Each month, your existing balance grows by the effective monthly rate, and then your contribution is added on top. This means contributions made earlier in the timeline have more time to compound than later ones.
Why does the calculator use a monthly loop instead of a single formula?
A monthly loop handles any compounding frequency and monthly contributions consistently and correctly, including edge cases like a 0% interest rate, without needing a different formula for each combination.
What is "total interest" versus "total contributed"?
Total contributed is your initial principal plus every monthly contribution you made. Total interest is whatever is left of your final balance after subtracting total contributed — the actual growth generated by compounding.
What does the annual contribution step-up do?
It increases your monthly contribution by a fixed percentage every 12 months, modeling a raise or a plan to save more over time — a common way to keep pace with rising income.
What is the inflation-adjusted "real" balance?
It divides your final balance by (1 + inflation rate) raised to the number of years, showing what that balance is worth in today's purchasing power. It only appears once you enter an inflation rate above 0%.
Can I see my balance grow year by year?
Yes — the chart plots your balance against your cumulative contributions over time, and the table below it breaks the same numbers down year by year, including interest earned each year.
Can I see results in a different currency?
Yes — pick a currency from the selector above the inputs. It only changes how amounts are displayed and is remembered for your next visit; the underlying math is currency-agnostic.