How unit conversion works
Converting units means multiplying by the right factor. Most converters, including this one, pick a base unit for each category (meters for length, kilograms for weight) and convert everything through it. To go from feet to miles, the tool multiplies your number by the size of a foot in meters, then divides by the size of a mile in meters.
A worked example: 1 mile is 1609.344 meters and 1 foot is 0.3048 meters, so 1 mile equals 1609.344 / 0.3048 = 5280 feet.
Temperature is the exception, because Celsius, Fahrenheit and Kelvin differ by an offset as well as a scale. The tool converts the value to Celsius first (212 degrees Fahrenheit becomes (212 - 32) x 5/9 = 100) and then to the target scale.
Why one hub for many categories
Everyday tasks rarely stay inside one category. Cooking involves volume, weight and temperature. Travel involves distance and speed. Working with files means data sizes. With ten categories on one page you can switch instead of hunting for a separate tool.
The hub covers Length, Weight, Temperature, Area, Volume, Speed, Data, Time, Pressure and Energy. Typical uses include turning a recipe in cups into milliliters, translating mph to km/h, comparing acres with hectares, or checking how many megabytes are in a few gigabytes. If you want a single category on its own page, there are dedicated tools such as the length converter and the temperature converter.
How to use the converter
- Choose a category with the buttons at the top. The active one is highlighted.
- Type the number you want to convert into the From box.
- Pick the starting unit in the dropdown under it.
- Pick the target unit in the dropdown under To.
- Read the answer in the result box, which updates as you type or change a unit.
A category starts with its first unit as the source and its second as the target, for example Millimeters to Centimeters. Switching category resets both dropdowns to that category's first two units, so choose the units you need. The calculation runs in your browser and nothing is sent anywhere.
Accuracy, rounding and unit definitions
Results are rounded to six decimal places (four for temperature), so very small values may show as 0. The factors are fixed values inside the tool, and a few are worth knowing:
- Data uses decimal units: 1 gigabyte is 1000 megabytes. Some operating systems use 1024-based steps, so sizes may differ from your file manager.
- Cups are treated as 0.24 liters (a metric cup), while gallons, quarts and fluid ounces use US values.
- Tons are metric tons of 1000 kilograms.
- Calories are small calories (4.184 joules each), and Kilocalories are the food-label Calories.
- Factors for units like ounces and pounds are rounded to about six significant digits, so results are very close but not exact.
For engineering, medication or other precise work, confirm against an authoritative source.