WiseCalc

Compound Interest Calculator

See the power of compound interest on your investments over time with different compounding frequencies.

Long-term wealth building

See how consistency and time can outrun trying to ‘time the market.’

Model how an initial investment plus monthly contributions can compound into a much larger balance over years or decades.

Makes the gap between contributions and growth obvious
Lets you test rate, time horizon, and compounding assumptions fast
Useful for retirement, college, emergency-fund, and goal planning
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$0$1,000,000
$
$0$10,000
%
0%20%
years
0 years50 years
Compounding

Uses a nominal annual rate. Contributions are grouped and added at the end of each selected compounding period. A final partial period uses fractional-power growth and prorated contributions at its end. This estimate excludes taxes, fees and rate changes.

Final Balance
$144,573
Total Contributions
$58,000
Total Interest Earned
$86,573
Interest Ratio
149%
of contributions

Growth Over Time

What your result means

The key number isn’t just the final balance — it’s how much of that total comes from your own contributions versus growth doing the heavy lifting over time.

Compounding is gaining traction

Your balance is large enough that growth is starting to make a visible contribution.

Staying consistent and avoiding interruptions can matter more than constant strategy changes from here.

Related Guides

Helpful articles and resources related to this calculator.

Compound Interest: The Most Powerful Force in Finance

A practical breakdown of the formula, time horizon, and why starting early matters so much.

How to Calculate ROI on Any Investment

Use ROI thinking alongside compounding projections to compare opportunities more clearly.

Related Calculators

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Investment Return Calculator

Compare annualized returns and total growth across investments.

Savings Goal Calculator

Work backward from a future target to the monthly amount you need.

Retirement Savings Calculator

Turn compounding assumptions into a retirement-focused plan.

What to do next

Turn the projection into an actual savings system while the math is fresh.

Lock in an automatic monthly contribution

The projection only works if the contribution habit is real and repeatable.

Test a higher savings rate

Even a modest monthly increase can change the long-term curve more than expected.

Connect the result to a real goal

Map the projection to retirement, a home down payment, or a future spending milestone.

Work backward from a savings goal

Define your inputs

Initial investment is the starting balance. Monthly contribution is new money added each month, not interest. Annual interest rate is a nominal rate, not APY. Select monthly, quarterly or annual compounding; daily compounding is not available on this page.

Worked example: monthly contributions

Enter $10,000 initially, $100 per month, 6% nominal annual interest and 1 year; select Monthly. Each month: new balance = previous balance × 1.005 + $100. After 12 months, the balance is $11,850.33, displayed as $11,850. Contributions including the starting amount are $11,200; interest is $650.33, displayed as $650.

Contribution timing and limits

Contributions are grouped at the end of each selected compounding period: $100 monthly becomes $300 per quarter or $1,200 per year. These are simplified timing assumptions, not a simulation of every deposit date. A final partial period uses fractional-power growth, followed by a prorated contribution at its end. Total contributions = initial investment + monthly contribution × 12 × years. The chart ends at the selected term.

The rate is constant. Taxes, fees, inflation and market fluctuations are excluded. The projected balance is a scenario, not a promised investment return. This page does not display a separate effective annual rate.

Comparing a CD instead

If you have a single deposit and an advertised APY, use the CD calculator. Its APY already includes compounding; this page starts from a nominal annual rate.