Principal starts the curve
Your starting balance gives compounding something to build on. A larger base makes each percentage point worth more.
Watch your money grow over time
Compound interest adds earnings to your balance, then lets those earnings earn too. Time, rate, and consistency do the quiet heavy lifting.
$0
ending balance
$0
interest earned
0 yrs
time invested
Final balance
$0
Total invested
$0
Interest earned
$0
Balance
Total invested
Compound interest turns time into momentum
Contributions keep feeding it
Regular deposits add fresh money to the balance. Even modest monthly additions can change the shape of the ending total.
Interest earns interest
Once earnings stay invested, they become part of the next period's balance. That is where the curve begins to bend upward.
The core formula
For a single starting amount, the standard compound interest formula is:
A = P(1 + r/n)^(nt)
A is the ending amount, P is principal, r is annual rate, n is compounding periods per year, and t is time in years.
Year-by-year growth
| Year | Balance | Total invested | Interest earned | Annual gain |
|---|