Unit Converter guide
Convert common length, weight, and temperature measurements with accurate conversion factors.
What this tool does
The converter translates a value from one supported unit into another. Length options include metric and imperial units from millimeters to miles. Weight options range from milligrams to kilograms, pounds, ounces, and stone. Temperature conversions support Celsius, Fahrenheit, and Kelvin.
Length and weight calculations first multiply by an exact or standardized factor to reach a shared base unit, then divide by the destination factor. Temperature uses scale-specific formulas because Celsius, Fahrenheit, and Kelvin have different interval sizes and zero points.
How to use it
- Choose Length, Weight, or Temperature.
- Enter the value to convert.
- Select the source and destination units.
- Read the live result.
- Use the swap button to reverse the conversion.
Benefits
- Common metric and imperial units in one place
- Live results as values or units change
- Correct temperature offset formulas
- High-precision calculations with readable output
Understanding precision
Calculations use JavaScript floating-point numbers and the defined conversion factors, while the interface limits unnecessary displayed decimals for readability. Swapping the units uses the current unrounded result as the new input, which helps reduce avoidable display-rounding loss.
Some units have exact definitions: one inch is exactly 0.0254 meters, for example. A converted measurement cannot be more accurate than the source measurement, so preserve only the number of significant digits appropriate for your input.
For temperature, the tool permits any mathematical input, including Kelvin values below absolute zero. Such a conversion can be calculated but is not physically meaningful; the tool does not validate scientific plausibility.