Writing
Why the numbers behave that way
A calculator gives you an answer. These explain the answer — where the published figures come from, which assumptions are doing the work, and the places where a number that looks precise is really an estimate.
Loans & mortgages · 6 min
Why your lender's quote doesn't match the calculator
A calculator gives you principal and interest. A lender quotes PITI, plus pricing set by your credit file. Here is every line between the two.
Loans & mortgages
28 years
of compounding a year-two dollar avoids
What paying an extra $100 a month actually does
Salary & pay
7.65%
goes to FICA before income tax is touched
Where your paycheck actually goes
Salary & pay · 4 min
The 2,080-hour year is a fiction
Every hourly-to-salary conversion assumes 40 × 52. Almost nobody works that year — and the gap runs in both directions.
Converters · 5 min
Why your bank's exchange rate is worse than the one you looked up
The rate you look up is the mid-market rate, and nobody sells currency to the public at it. What the spread really costs you.
Converters
2 or 3
days from Monday to Wednesday — both are used
Date maths is harder than it looks
Kitchen
30%
spread between a scooped and a sifted cup
A cup of flour is not a weight
Kitchen · 4 min
Gas mark, fan, and the twenty-degree rule
Fan ovens cook hotter than the dial says, gas marks are not linear, and recipes rarely tell you which they mean. How to read any oven instruction.