Conversion Calculators

Length, weight, temperature, and distance converters with exact factors, both directions, and quick-reference tables.

Exact or standard unit conversions for length, weight, temperature, and distance — bidirectional, with tables and both-direction worked examples.

Conversion calculators apply published conversion factors (for example, 1 inch = 2.54 cm exactly, or the international mile definition). Edit either field and the other updates so you can work from the unit you already know — handy when UK/EU metric labels meet imperial product specs.

These pages are intentionally substantial: the factor used, formulas both ways, everyday examples, quick-reference tables, common mistakes, and notes about rounding. They are not currency or timezone converters.

Pick a converter below when you need a reliable number for cooking, travel, fitness tracking, weather, or schoolwork. For a written overview of the same factors, read our metric and imperial conversions guide.

Each converter focuses on one pair of units so the explanation stays specific — pounds versus kilograms is not the same problem as Fahrenheit versus Celsius, which needs an offset as well as a scale factor.