Guides & explainers
Plain-language writing about the maths behind everyday decisions — what the formulas mean, where they mislead, and how to check the numbers yourself.
How a loan EMI is built — and why early payments are almost all interest Your monthly repayment never changes, but what it is made of shifts every month. Understanding amortisation shows why overpaying early saves so much. Read the guide The metric-imperial conversions actually worth memorising You do not need conversion tables for everything. A handful of anchors, plus two mental tricks, cover almost every day-to-day conversion. Read the guide BMI: what it measures, and four things it cannot tell you BMI is a useful population screening tool and a blunt individual one. Here is what the number means, where it misleads, and what to look at alongside it. Read the guide Compound interest, explained with numbers you can check yourself Why time matters more than rate, what compounding frequency really changes, and the Rule of 72 — with worked figures you can verify. Read the guide Margin vs markup: the pricing mistake that quietly costs you money Margin and markup describe the same profit against different baselines. Confusing them leads to underpricing — here is the difference, with a conversion table. Read the guide