Articles

Home rebuild cost is floor area times a local build rate, plus extras. Learn why it differs from market value and how to avoid being underinsured.

Birthstones by month explained: the modern list, why some months have two or three stones, how the lists changed since 1912, and how tough each stone is.

Work out the exact age difference between two people in years, months and days, with month-end and leap-day rules and why the age ratio shrinks.

Learn how to calculate your marks percentage: marks obtained divided by maximum marks x 100, totals vs averages, best five subjects, and target marks.

JSON vs XML side by side: the same record in both, attributes vs keys, arrays, comments, schemas, and the pitfalls of converting XML to JSON.

Average fixed cost is total fixed cost divided by output. Learn the formula, why the AFC curve always falls, and how AFC differs from AVC and ATC.

The 70/20/10 budget rule splits take-home pay into living costs, savings or debt, and giving. See the math, a $4,200 example, and how it compares to 50/30/20.

Learn how purchasing power parity compares salaries across countries, why it differs from exchange rates, and how to scale pay by price levels.

COBRA can cost up to 102% of the full plan price, or 150% in disability extension months. See the math, the time limits, and the payment deadlines.

Prop slip compares how far your propeller should push the boat with how far it really goes. Learn the formula, the gear ratio step, and what a reading means.