Every one is free, needs no account, and computes in your browser — nothing you type reaches us. Each shows the formula and the intermediate quantities, because a number with no working is worth almost nothing in a marked script.
179 more are being added at ten a day. Everything listed here is finished and working — nothing below is a placeholder.
Grades, credits and the arithmetic of academic standing. These are the most used tools in the library and the ones students most often need mid-term rather than at the end.
Interest, lending, pricing and tax. Figures are illustrative and none of it is financial advice — these are coursework tools.
The general-purpose arithmetic, number theory and descriptive statistics tools. The largest topic in the library.
Inference and modelling. All of these take a pasted column of data, report n, and show the intermediate quantities a marker expects to see.
Counting, timing and citing. Nothing here writes anything for you — they measure what you have written.
The library is large but not sprawling: every tool is one of seven shapes. Knowing which one you are looking at tells you what it wants from you before you read a single label.
2–6 numeric inputs, one headline answer, the formula shown beneath it.
47 toolsA table the user adds rows to, with a running total.
15 toolsA large textarea with live counts. No submit button.
10 toolsOne tool, several modes; the control changes which inputs show.
2 toolsDates and durations in, a schedule or timeline out.
5 toolsPaste a column of numbers; n-count, statistics and a small chart out.
21 toolsA formula in, worked steps out — rendered mathematics, not one number.
0 toolsThese tools compute. They do not explain a method you have not been taught, and they do not sit an assessment for you. If the difficulty is that you cannot follow the method, a worked answer from a calculator will not survive the next question on the paper.
When that is the situation, the honest move is a tutor, your module leader, or a worked model answer you can study against your own attempt. We sell the third of those, and we would rather say so plainly here than dress it up as a feature of a free tool.
Calculators are provided for study and planning. Results are not official records, professional advice, or a substitute for your institution's own figures.