Calculator MethodologyScenario Planning
Beginning vs End-of-Month Contributions in an Investment Calculator
Learn why contribution timing changes a projection, how the calculation works, and how to compare tools using consistent assumptions.
Investment AssumptionsScenario Planning
How to Choose a Return Assumption for an S&P 500 Calculator
A practical framework for testing conservative, central, and higher return assumptions without treating a calculator as a forecast.
Investment Assumptions
How Inflation Changes an S&P 500 Investment Projection
Learn the difference between nominal and inflation-adjusted balances, the formula used, and the limits of using one fixed inflation rate.
Investment Assumptions
How Investment Fees Compound Over 10, 20, and 30 Years
See why a small annual fee can create a larger long-term difference and how to model fees without double counting them.
Scenario Planning
Lump Sum vs Dollar-Cost Averaging: What a Fixed-Return Model Shows
Compare investing a lump sum immediately with spreading it over time, including what fixed-return calculations can and cannot tell you.
Investment AssumptionsCalculator Methodology
S&P 500 Price Return vs Total Return: What Your Calculator Is Measuring
Understand the difference between S&P 500 price return and total return, how dividends change the result, and which assumption to use in a projection.
Calculator MethodologyScenario Planning
Why S&P 500 Calculators Give Different Results
Learn why S&P 500 calculations differ when tools use different dividend, contribution timing, compounding, fee, tax, inflation, and return assumptions.