Universal Unit Converter

One tab for the conversions that actually come up: length, weight, area, volume, digital storage, speed, and temperature, each with the everyday units from recipes, shipping forms, spec sheets, listings, and homework. Instead of searching "5.8 feet in cm" fifteen times a week, keep one converter that answers all of it.

The design choice that makes it fast: there is no "to" unit. Pick the category, type an amount, say which unit it is in — and the full grid fills with every unit's equivalent at once, updating live. Enter 10 kilometres and miles, metres, feet, yards, and inches all appear together; no target selection, no convert button. Temperature gets its own handling because Celsius, Fahrenheit, and Kelvin are offset scales rather than simple multiples.

Two conventions worth knowing. The volume units are the US definitions (gallons, cups, fluid ounces), which is what most online recipes and product labels mean — UK imperial measures differ by up to 20%. And the Storage tab uses the binary convention, where 1 kilobyte = 1,024 bytes — the way operating systems report sizes; drive manufacturers advertise in decimal thousands instead, which is why a "1 TB" drive shows as ~931 GB in Windows. For per-unit precision controls, copy buttons, and reference tables, each category also has a dedicated converter — this one optimizes for having everything a tab-click away.

Each category (except temperature) converts through a base unit: your amount is divided by the From unit's factor to reach the base, and every grid cell multiplies the base by its own unit's factor. That single pass is why the whole grid updates in one keystroke, and why chained conversions cannot accumulate error — everything derives from the same base value.

Temperature cannot work that way because its scales share no common zero: 0 °C is 32 °F, not 0 °F. Its tab applies the real formulas — °F = °C × 9/5 + 32 and K = °C + 273.15 — pivoting through Celsius.

This is the breadth tool: one From unit per category, a fixed everyday unit set, six-decimal display, and no per-card copy, precision control, or reference tables — the dedicated converters carry those. Volume uses US definitions only, and Storage uses the binary (1,024) convention only. Temperature covers the three main scales.

Each multiplicative category stores factors relative to a base unit; conversion computes base = amount ÷ factor(from) and renders every cell as base × factor(unit), formatted to six decimal places. Temperature is handled separately with affine Celsius-pivot formulas. All computation is client-side and instant.

Anyone whose week contains assorted small conversions — cooks, shoppers on international sites, students, travellers — and who wants one tab instead of seven. Specialists doing repeated precise work in a single category are better served by that category's dedicated converter.