See how your money grows exponentially over time with the power of compounding. Adjust your starting amount, monthly savings, and expected return to visualize your wealth trajectory.
In Wealthos, these values come automatically from your added accounts, tracked income, expenses, and goals.
Wealth in 10 years
417k
Total saved
240k
Earned interest
+147k
Compound interest is interest calculated on both the initial principal and the accumulated interest from previous periods. Unlike simple interest, which only applies to the principal, compounding means your returns generate their own returns — creating exponential growth over time. This is often called the eighth wonder of the world.
A quick mental shortcut: divide 72 by your annual interest rate to estimate how many years it takes to double your money. At 7% annual return, your investment doubles roughly every 10 years. At 10%, it doubles every 7.2 years.
The biggest factor in compound interest is time. Starting 10 years earlier can result in significantly more wealth, even if you invest the same total amount. Early contributions have more compounding periods, making each dollar invested earlier worth more than a dollar invested later.
A = P(1 + r/n)nt + PMT × [((1 + r/n)nt - 1) / (r/n)]
This calculator uses the compound interest formula with monthly contributions. P is your starting amount, r is the annual interest rate, n is 12 (monthly compounding), t is years, and PMT is your monthly contribution (income minus expenses). The chart shows your projected balance at each year.
Starting with $10,000 and contributing $2,000/month at 7% annual return: after 10 years you'd have approximately $358,000 — of which $250,000 is contributions and $108,000 is compound interest. After 20 years, the balance reaches roughly $1,050,000, with compound interest contributing over $570,000.
Try increasing your monthly contribution by just $100 to see how even small changes compound into large differences over decades.
Use 7% as a conservative baseline for stock market returns after inflation. If you want to see nominal (before inflation) projections, try 10%.
Compare two scenarios: starting with $10,000 today vs. waiting 5 years and starting with $30,000. You'll often find that starting earlier wins despite the smaller initial amount.
If you have a specific goal in mind, switch to the Savings Goal calculator to reverse-engineer the monthly savings needed.