無料オンライン複利計算機

Simple interest is calculated only on the principal. Compound interest is calculated on the principal PLUS accumulated interest, so your balance grows faster over time — this is the "interest on interest" effect.

More frequent compounding means slightly higher returns. Daily compounding earns a bit more than monthly, which earns more than annual. The difference grows with larger balances and longer time horizons.

Yes — enter a monthly contribution amount in the Additional Contribution field to see how regular deposits accelerate growth through compound interest.

The Rule of 72 estimates how long it takes to double your money: divide 72 by your annual interest rate. At 8%, money doubles in about 9 years. Verify this by running the calculator with your rate.

It shows mathematical compound growth. Real returns may differ due to taxes, fees, and variable rates. Use it for planning estimates, not as financial advice.

Yes, the 複利計算機 on Allio Tools is completely free with no sign-up or registration required. It works directly in your browser.

複利による投資の成長を計算します。 No data is sent to a server — everything runs locally in your browser for maximum privacy and speed.

No installation needed. The 複利計算機 runs entirely in your web browser on any device — desktop, tablet, or mobile.

Completely safe. The 複利計算機 processes everything locally in your browser. No input data, results, or usage information is ever transmitted to or stored on any server.

After the page loads for the first time, the 複利計算機 works without an internet connection for all client-side processing. Tools that fetch live external data (such as DNS or network lookups) require an active connection.

The 複利計算機 uses standard, well-established mathematical formulas used by professionals worldwide — the same ones used by banks, financial advisors, and accounting software. Results are as accurate as the inputs you provide. See our <a href="/methodology/">Methodology page</a> for formula sources and references. For financial decisions, always verify with a qualified professional.

Yes. Copy the result number or screenshot the page to share via message, email, or social media. You can also bookmark and share the tool URL directly — the 複利計算機 opens instantly for anyone with a modern browser, no account needed.

Yes. The 複利計算機 is built with standard browser APIs and works on all modern browsers including Chrome, Firefox, Safari, and Edge — on both desktop and mobile. No plugins, extensions, or third-party software are required.

Select and copy the result text to paste into any document or app. For image tools, a Download button saves the file directly to your device. Your browser's built-in screenshot function also captures results quickly. No account or login is required.