How this compound interest calculator works
Net Worth Live is a compound interest calculator for watching modelled wealth change over time. Enter a starting amount, monthly savings and an assumed annual return. The main figure shows the model’s current total value, not just the return earned. You supply the starting amount yourself: the tool does not calculate your net worth from a list of assets and debts.
The growth rate shows the current change in value per unit of time. It combines modelled investment return and added savings, with each component shown separately. The total value can also decrease. Times to accumulate additional amounts at the current rate assume that rate stays constant; they are not the same calculation as future value projections.
Future values start from the current calculated value and assume your selected return and savings continue. Compare different starting amounts, savings levels and return assumptions by changing the inputs. The model includes compound growth and a steady flow of savings, but excludes taxes, fees, inflation and market fluctuations. Calculations run in your browser without fetching bank or stock-market data. Results illustrate assumptions: they do not predict your actual wealth, guarantee returns or provide personal investment advice.
Read more about the calculation model and its limitations.
Frequently asked questions
What does compound interest mean in this calculator?
Previously accumulated returns are included in the value used to calculate further returns. For example, a starting amount of 100 becomes 107 over one model year at an assumed 7% annual return with no added savings. This illustrates the calculation, not a promised return.
How are monthly savings included?
Monthly savings are modelled as a continuous, steady flow: a total of 12 times the monthly amount is added over one model year. Savings receive the assumed return from the time they enter the model. Separate monthly deposits and their payment dates are not simulated.
What does watching growth live mean?
The displayed value updates using your device clock and selected assumptions, not bank or market data. Time spent with the page closed is also included when you return to a saved calculation. Paused freezes the displayed time, not the passage of time in the model.
How do future projections differ from times at the current rate?
A future value projection continues compound growth and savings from the current calculated value. A time at the current rate instead shows how long an additional amount would take to accumulate if the current combined return and saving rate stayed constant. Neither is a market forecast.
Can the calculated value decrease?
Yes. A negative return assumption can reduce the total value if added savings do not offset the decline. The model does not simulate market fluctuations or account for taxes, investment fees or inflation, so results do not represent inflation-adjusted purchasing power.
Which currencies can I use?
The English calculator supports EUR, USD, GBP, CAD, AUD and NZD. The Finnish calculator always uses euros. Choosing a currency relabels the same numeric amounts without changing their values, using exchange rates or performing currency conversion.
Are my calculations and inputs saved?
Calculation data is processed in your browser. Your calculation period and interface preferences can be saved in this browser’s local storage when it is available. The application does not send financial inputs or results to a server; general website analytics is separate. Read more about privacy and browser storage.
