Guides
Plain answers to money decisions, with the numbers worked through.
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Should you pay off a 6 to 7% mortgage or invest?
At 6 to 7%, the math is close. One worked example finds the break-even and the two mistakes that skew it.
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Why do Coast FIRE calculators disagree on my number?
A worked Coast FIRE example, and why mixing up before- and after-inflation returns changes the answer by more than 2x.
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Will my savings last in retirement? Years by withdrawal rate
How many years a portfolio lasts at a given withdrawal rate and real return, why a flat return hides sequence risk, and what the 4% rule really tests.
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How many months of expenses should your emergency fund cover?
Count months of essential expenses, not take-home pay, then add months for variable income, dependents and long job searches.
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Should you count the 401(k) match when comparing job offers?
Turn an employer match into dollars, compare two offers on salary plus match, and check vesting before you count it.