Money guides
Plain-English explainers on the ideas behind our calculators. Each guide covers what a concept means, why it matters, and how to put a real number on it.
Debt Avalanche vs Debt Snowball: Which Pays Off Faster?
Two proven payoff methods compared, and why the size of your monthly payment matters more than either one.
How the 4% Rule Actually Works
Where the famous retirement rule came from, the 25x shortcut, and the assumptions it quietly makes.
APR vs APY: The Difference That Costs You Money
Why the same interest rate can be quoted two ways, and how compounding makes card debt grow faster than the sticker rate.
What a 1% Investment Fee Really Costs Over 30 Years
A one percent fee sounds tiny. Over three decades it can quietly claim a six-figure share of your portfolio.
How Big Should Your Emergency Fund Be?
The 3-to-6-months guideline, who needs more, where to keep the money, and how to build it a month at a time.
Are mortgage points worth it?
What a point actually buys you, and the break-even test that decides it.
PMI, explained without the jargon
Who pays it, what it costs, and how to get rid of it.
Your debt-to-income ratio, and why lenders obsess over it
The 28/36 thresholds, what counts as debt, and a worked example.
How credit card interest actually works
Daily accrual, the grace period, and why minimums keep you in debt.
Renting vs buying: the actual maths
Why rent vs mortgage payment is the wrong comparison.
Does compounding frequency actually matter?
Daily vs monthly compounding, and why the difference is smaller than banks imply.
CD ladders: boring, and that's the point
Staggered maturities, steady access, and the trade-offs.
When refinancing actually makes sense
The break-even test, with a full worked example.
Coast, lean, fat: the flavours of FIRE
The FIRE variants and the numbers behind each.
The debt snowball shouldn't work, but it does
The maths says avalanche. Behaviour says otherwise.