Compound interest calculation/accumulation investment simulator (asset formation simulation) | ZeroTools

You can calculate the expected future asset amount from the initial investment amount, monthly savings amount, yield, and number of years, and visually compare the difference between compound interest and simple interest. It is a convenient web tool that operates completely locally and safely without sending data to an external server.

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Article Index
Chapter 1

Technical Specifications & Architecture

How are contributions calculated? The simulation divides the annual rate by twelve. Each month it adds interest to the balance, then adds the monthly contribution.

Is the result a guaranteed return? No. It uses a constant assumed rate and does not calculate actual proceeds after taxes, fees, or price changes.

Can I compare simple and compound interest? The annual table and chart compare both using the same input assumptions.