Unit Converter
Convert between common length, weight and temperature units instantly — pick a category, enter a value, and choose your from/to units.
How to Use This Tool
Choose a category
Length, weight, or temperature.
Enter your value
The number you want to convert.
Pick your "from" and "to" units
The conversion updates live as you change either.
Read the converted result
Shown instantly below the form.
About the Unit Converter
Converting between measurement systems — metric and imperial for length and weight, or Celsius and Fahrenheit for temperature — comes up constantly when working across countries, following recipes, reading specifications, or communicating with people using a different system than you're used to.
This tool covers the three most commonly needed conversion categories: length (millimeters through miles), weight (grams through pounds), and temperature (Celsius, Fahrenheit, and Kelvin) — with live conversion that updates instantly as you type or change units.
Temperature conversion in particular differs from length and weight, since it isn't a simple multiplication (Celsius and Fahrenheit have different zero points), so this tool applies the correct formula for each specific temperature unit pair rather than a generic ratio.
Frequently Asked Questions
What units are included in the length category?
Millimeters, centimeters, meters, kilometers, inches, feet, yards, and miles — covering both the metric and imperial/US customary systems for everyday length conversions.
What units are included in the weight category?
Grams, kilograms, ounces, pounds, and metric tons — covering common weight units from both the metric and imperial/US customary systems.
Why is temperature conversion different from length or weight?
Length and weight conversions are simple multiplication (multiply by a fixed ratio), but temperature scales have different zero points — 0°C is not the same physical temperature as 0°F — so converting requires an offset calculation in addition to scaling, using a different specific formula for each unit pair.
How accurate are the conversions?
Conversions use standard, precise conversion factors and are shown rounded to a reasonable number of decimal places for readability — accurate enough for virtually all everyday, cooking, DIY, and general reference purposes.
Can I convert between units in different categories, like weight to length?
No — unit conversion only makes sense within the same category of measurement, since weight and length measure fundamentally different physical properties. Select the correct category first, then convert between units within that category.
Is my input saved or uploaded anywhere?
No — all conversion happens locally in your browser using JavaScript. Nothing you enter is uploaded or stored.