What is compound interest?
Compound interest is interest calculated on both the initial principal and accumulated interest. Unlike simple interest, compound interest 'snowballs' - each period's interest earns interest in future periods.
Quick Marketing Tools
Compound Interest Calculator
Calculate compound interest with interactive growth charts. See contribution breakdowns and compare scenarios visually.
What this tool does
Calculate compound interest with interactive growth charts, contribution breakdowns, and scenario comparisons.
Use the controls on this page to enter the required details, review the generated result, and copy or export the output for your workflow.
Inputs are processed in the browser where supported. Review assumptions and outputs before using the result in a report, document, or client workflow.
How to use it
- Open the tool interface on this page.
- Add the numbers, text, URLs, images, or PDFs the tool asks for.
- Review warnings, previews, totals, file details, or validation notes before using the output.
- Copy, download, export, print, or save the result when the page confirms the output is ready.
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Helpful questions
How often should interest compound?
More frequent compounding yields more growth. Daily compounding earns slightly more than monthly, which earns more than annually. For most savings accounts and investments, the difference between daily and monthly is small.
What's the Rule of 72?
The Rule of 72 estimates how long it takes to double your money. Divide 72 by the annual interest rate: at 8%, money doubles in about 9 years (72/8). It's a quick mental math shortcut.
Does this account for inflation?
The basic calculation uses nominal returns. For real (inflation-adjusted) returns, subtract the expected inflation rate from your interest rate. A 7% return with 3% inflation yields ~4% real return.