How the Unit Converter Works
Pick a category — Length, Weight, or Temperature — then choose the units you're converting from and to. Type a value in the "From" field and the "To" field updates instantly as you type; use the swap button to flip the two units without re-entering anything.
Length and weight conversions use fixed multiplication factors against a common base unit (meters for length, grams for weight), so results are exact to floating-point precision. Temperature is different — Celsius, Fahrenheit, and Kelvin aren't simple multiples of each other, so those three use their proper conversion formulas (for example, °F = °C × 9/5 + 32) instead of a multiplier.
This covers the everyday conversions people actually search for: recipe measurements, converting a shopping-site's imperial sizing to metric (or vice versa), body weight and height, travel temperature checks, and quick unit sanity-checks for anything from DIY projects to schoolwork.
Frequently Asked Questions
How accurate are the conversions?
Length and weight conversions use internationally standardized conversion factors (for example, exactly 2.54 cm per inch) and are accurate to the precision your browser's floating-point math allows — more than enough for any everyday use.
Why is temperature handled differently from length and weight?
Length and weight units are proportional to each other (double the meters, double the feet), so a single multiplier converts between any two. Temperature scales have different zero points — 0°C isn't 0°F — so converting between them needs the actual formula, not just a multiplication factor.
What units are supported?
Length: millimeters, centimeters, meters, kilometers, inches, feet, yards, and miles. Weight: milligrams, grams, kilograms, metric tonnes, ounces, and pounds. Temperature: Celsius, Fahrenheit, and Kelvin.