How We Calculate
Our calculators use standard financial formulas applied to the values you enter.
Standard formulas
Our tools use well-known financial mathematics such as compound interest, loan amortization, percentage allocation and inflation adjustment. Each calculator page explains its own formula and the inputs it uses.
Your inputs drive the result
Results depend entirely on the numbers and assumptions you enter, such as interest rates, contribution amounts and time periods. Change an input to see how the result changes.
Estimates, not guarantees
Calculations are estimates for planning and education. Real-world results can differ because of market changes, fees, taxes and personal circumstances.