Guides

In-depth how-tos for getting the most out of Calculateus.

Car specifications list power in horsepower, kilowatts, or both depending on the market. Here's the exact conversion and why it matters.

Time conversion seems obvious until you need to convert across several units at once. Here's how to do it cleanly, with a worked example.

Nutrition labels use Calories, science uses joules. Here's how the two energy units relate and why food 'Calories' aren't quite what they sound like.

A '1TB' drive often shows less than 1TB in your operating system. Here's the binary-vs-decimal math behind the discrepancy.

Area units scale differently than length units — doubling a length conversion factor doesn't double the area conversion. Here's why.

Speed limits and car speedometers use different units around the world. Here's the exact conversion factor and a quick mental shortcut.

Recipe volume units — cups, tablespoons, milliliters — trip up even experienced cooks. Here's how they actually relate.

The real Celsius-to-Fahrenheit formula is precise but awkward for mental math. Here's the exact version and a useful quick estimate.

Weight conversion between metric and imperial units uses a single key factor. Here's how it works and a few benchmarks worth remembering.