Mortgage Payoff vs. Investing: When the Math Changes
Compare paying extra toward a mortgage versus investing the same cash flow, and learn how interest rates, taxes, liquidity, risk, and time horizon change the result.
Insights
The math behind the decisions.
Most financial tools give you a number. CompoundLab Insights explains what that number is actually saying - and where it can mislead you. Each article is written to support a specific calculator, unpacking the assumptions, tradeoffs, and real-world context that the inputs can't capture on their own.
FIRE Number Explained: Why 25x Expenses Is Only a Starting Point
Understand how the FIRE number is calculated, why the 25x rule comes from a 4% withdrawal assumption, and why inflation, taxes, and flexibility matter.
What Return Assumption Should You Use in a Compound Interest Calculator?
Learn how to choose realistic investment return assumptions, compare conservative and optimistic scenarios, and avoid overconfidence in long-term projections.
How Investment Fees Quietly Reduce Long-Term Wealth
See how small annual investment fees can compound into large long-term costs, and learn how to compare gross return, net return, and fee drag.
Nominal vs. Real Returns: Why Future Money Is Not Today's Money
Learn the difference between nominal and inflation-adjusted returns, why purchasing power matters, and how to read long-term investment projections more carefully.
What a FIRE calculator is really telling you
A FIRE calculator can estimate your FIRE number and retirement age, but the real value is seeing which assumptions matter most before you build around them.
Should you pay off your mortgage early or invest instead?
Should you pay off your mortgage or invest instead? Learn how to compare the tradeoffs and test your own numbers with this calculator.
Choosing a reasonable long-term return assumption
A practical framework for setting return expectations that are useful for planning instead of optimized for optimism.
Nominal vs. real growth in portfolio planning
Why compound growth can look impressive on paper but still miss the purchasing-power question investors actually care about.
How recurring contributions reshape long-horizon outcomes
A guide to seeing how smaller monthly deposits can influence the final balance as much as headline return assumptions.