Most tool sites file everything under a single long alphabetical list, which works only if you already know the name of the thing you are looking for. Utilario groups tools by the problem instead. Someone working out how much paint to buy does not think "area calculator"; they think about a room. Someone splitting a restaurant bill does not think "division"; they think about money. The categories below follow that logic, so you can arrive with a task rather than a search term.
The split is deliberately coarse. Nine groups is few enough to scan in one go, and each one holds tools that genuinely belong together: Calculators for percentages, ratios and everyday arithmetic; Date & Time for anything measured in days, hours or time zones; Text for counting, sorting and cleaning up writing; Converters for units that cross between metric and imperial; Money for prices, tax, loans and running costs; Files and Images for work that happens to your own documents and pictures without uploading them anywhere; Home for the measuring and estimating that comes with decorating; and Utilities for the small generators and converters that do not fit neatly elsewhere.
A tool can appear in more than one category when that is genuinely useful — the fuel cost calculator is filed under Money and Utilities, because it is a spending question and a driving question at the same time. Every category page lists its tools with a short description of what each one does, so you can tell them apart before clicking.