Calculators

Unit conversions, loan/EMI amortization, BMI and percentage math — all offline.

Loan amortisation is the one worth understanding rather than trusting. Each payment is the same size, but its split is not: early payments are mostly interest because interest is charged on the outstanding balance, and only as the balance falls does the principal share grow. That is why overpaying early saves disproportionately more than overpaying late.

BMI deserves its caveat stated plainly. It is mass divided by height squared, devised in the 1830s as a population statistic, and it cannot distinguish muscle from fat or account for build — which is why it misclassifies athletes routinely and should be read as one rough indicator rather than a diagnosis.