Converters
Convert between the units the world stubbornly refuses to agree on. Metric and imperial, Celsius and Fahrenheit, kilometres and miles, with live conversion as you type and a reference table of the values people look up most.
Unit conversion sounds trivial and is where a surprising amount goes wrong, because the hard part is rarely the arithmetic. It is knowing which of several definitions is meant, and that is where these tools put the effort.
Cooking is the clearest case. A cup is not a fixed weight, it is a fixed volume, so a cup of flour and a cup of sugar differ by more than fifty percent in grams. The cooking converter uses per-ingredient densities rather than one blanket ratio, and the recipe scaler adjusts quantities while flagging the things that do not scale linearly, such as tin sizes and baking times.
Sizing conversions have a similar problem: there is no single international standard, and the widely circulated charts disagree with each other. The shoe and ring size converters here are anchored on published reference points rather than interpolated from guesses, which is a mistake earlier versions of both genuinely made and which was corrected once it was caught. Each one states the anchor it uses.
For technical work, the number base converter handles binary, octal, hexadecimal and any base up to thirty six, showing the place values so the conversion is visible rather than magic. The Morse code translator plays audio at an adjustable speed, because Morse is learned by ear and learning it from a written chart produces a hard ceiling. The timezone converter handles the daylight saving transitions that make manual scheduling unreliable.
The general unit converter covers length, weight, volume, area, speed, temperature and data. Every conversion here is exact where an exact factor exists and states its rounding where one does not.