Models, not promises
Every calculator applies a defined set of rules to the values you enter. The result is reproducible under those rules, but it is not a prediction of market prices, bank rates or a personal tax outcome.
Each tool states its formula, rate convention, timing rules and exclusions beside the result so you can decide whether the model fits your question.
The main compound-interest calculator
The main calculator accepts nominal or effective annual rates. A nominal rate uses the selected compounding frequency to determine the annual growth factor. An effective rate already represents one year of compounding. The model then uses an equivalent monthly rate for 12 equal cash-flow periods per year.
Contributions can be placed at the beginning or end of a month and can increase once a year. The currency selector changes the display unit only; it does not convert a balance using an exchange rate.
Specialist models
The daily tool follows actual start and end dates and offers Actual/Actual, fixed 365 and fixed 360 day-count bases. The withdrawals tool models a constant annual return through equivalent monthly periods. The continuous-compounding tool uses the exponential formula, while its monthly additions remain discrete cash flows.
The formula solver covers one initial deposit without recurring contributions. The German ETF model combines an assumed gross return with the entered TER and shows sensitivity scenarios. Taxes, product-specific fees, changing market returns and exchange-rate changes are excluded unless a page expressly says otherwise.
Checking our work
We use automated checks for calculation logic, boundary cases and generated-page integrity. Tests reduce the chance of errors, but cannot prove that a model matches every real financial product. We do not claim individual financial-adviser review.