Everyday utility tools

The recurring bills, the kitchen and the journey. These are the calculations a household runs on a month rather than on a deadline, and the figures that decide every answer on this desk come from a bill, a meter, a label or your own record.

A utility tariff is the reason nothing here is filled in. Electricity is priced by a state regulator and delivered by a DISCOM that separates consumers by category and voltage; water is priced by a municipal authority that may bill in kilolitres, in connections or in tanker loads; a sewerage charge is a percentage on one bill and a separate line on another. Two households a few streets apart can pay different rates for the same unit, and a rate copied from the wrong circle produces a bill-shaped number with no relation to the one in your envelope. So the rates are fields, with the help text naming the document to read them from.

What is fixed on this desk is definitions, and there is a reason the cooking pages are the most exact on the site. A tablespoon is 15 ml, a metric cup is 250 ml, an avoirdupois ounce is 28.349523125 grams — those do not move, and the converter prints them beside the answer. A cup of flour is not one weight, though, because that number belongs to the ingredient and not to the arithmetic, so the page asks for a density rather than guessing one. The same principle runs through the recipe scaler: quantities multiply, and heat, time and pan size do not.

Four of the tools on this grid belong to another desk and are listed here as well — an age, a mileage, a fuel cost and a tax-inclusive price. They are not duplicated pages: each has one address and the second listing points at it, because a reader looking for a fuel cost should find it under everyday tools whether or not they think of a car as household. The arithmetic has not been rewritten for the second appearance either, so the two listings cannot give different answers.