Calculate compound interest with detailed analysis. See how investments grow over time with compounding returns, charts, and projections.

Compound Interest Calculator

Principal amount: $

Annual interest rate: %

Number of years:

Compounding frequency:

Monthly contribution: $ (optional)

Final amount: $196,946

Total interest earned: $126,946

Investment Analysis

Your $10,000 investment with $500 monthly contributions will grow to $196,946 over 10 years at 7.0% annual interest.

Principal Invested

$70,000

Your total contributions

Interest Earned

$126,946

From compound growth

Annual Growth

$12,695

Average per year

Effective Rate

7.23%

With compounding

Investment Growth Over Time

💡 Inflation-Adjusted Value

Assuming 3% annual inflation, your final amount would have purchasing power equivalent to $146,757 in today's dollars.

Year 1

$17,249

Year 5

$65,329

Year 10

$196,946

Year 20

$1,309,874

This compound interest calculator provides comprehensive investment analysis including growth charts, inflation adjustments, and detailed projections to help with financial planning and investment decisions.

About this Compound Interest Calculator

This compound interest calculator converts an amount from one year into its equivalent value in another, using official consumer price index data. Enter the amount and the two years, and the result shows the equivalent figure, the total cumulative inflation between them, and the average annual rate that produces the same change.

How the calculation works

The equivalent value equals your original amount multiplied by the ending year price index, then divided by the starting year index. Because inflation compounds, the average annual rate is always lower than the total change divided by the number of years.

Reading the result correctly

Prices rising is not the same as money losing value

If prices rise 25%, money does not lose 25% of its value, it loses 20%. Purchasing power is the starting index divided by the ending index, which is not the mirror image of the inflation percentage.

Averages are not personal

A consumer price index measures a fixed national basket. Your own experience depends on what you buy and where you live, so your personal rate can differ from the published figure.