Which calculator is missing?

The tools on this site do not come from a keyword list. They come from specific mistakes people make when buying freight. If you have one, tell us.

What is genuinely useful to know

The useful question is not "what topic interests you" but what do you work out now by hand or in a spreadsheet. That is where the gap is. The three most-used tools here started exactly that way:

None of those three would occur to somebody staring at a search engine. All three came from a person describing a problem they had had.

Tell us

The more specific the better. One real case beats a general description.

Only used to reply to you. There is no newsletter and no list.

What happens to what you write

This page works differently from the calculators, and it is worth saying so plainly. The calculators do their arithmetic inside your browser and send nothing anywhere. A form, by definition, does send what you write: that is the only way it can arrive.

Right now the button sends nothing by itself: it opens your own mail program with the text already written, and you decide whether to send it. Nothing leaves your computer until you press send in your own email.

What gets a reply and what does not

This site is maintained alongside a full-time job, so replies take days rather than hours. If your suggestion turns into a calculator, you will hear about it.