Unit Converter
Free online unit converter. Convert length, weight, temperature, volume, area and speed units instantly. Supports metric and imperial across 100+ unit pairs.
How Unit Conversion Works
Unit conversion is the process of converting a measurement from one unit to another. This is essential when comparing measurements across different systems, such as converting between metric and imperial units. Simply select the type of conversion, choose your units, and enter a value — the result is displayed instantly.
Common Conversion Categories
- Length: Convert between meters, kilometers, miles, feet, inches, and more.
- Weight: Convert between kilograms, grams, pounds, ounces, and tons.
- Temperature: Convert between Celsius, Fahrenheit, and Kelvin.
- Volume: Convert between liters, milliliters, gallons, cups, and pints.
- Speed: Convert between kilometers per hour, miles per hour, meters per second, and more.
- Area: Convert between square meters, square kilometers, square feet, acres, and more.
Metric vs Imperial Systems
The metric system (SI) is based on powers of 10 and is used in most countries worldwide. The imperial system is still used in the United States, United Kingdom, and a few other nations. Understanding conversions between these systems is useful for international communication and commerce.
Length Conversions
- 1 kilometer (km) = 1,000 meters (m)
- 1 meter = 100 centimeters = 1,000 millimeters
- 1 mile (mi) = 1.60934 kilometers
- 1 foot (ft) = 0.3048 meters
- 1 inch (in) = 2.54 centimeters
Weight Conversions
- 1 kilogram (kg) = 1,000 grams (g)
- 1 kilogram = 2.20462 pounds (lbs)
- 1 pound = 453.592 grams
- 1 ounce = 28.35 grams
- 1 metric ton = 1,000 kilograms
Temperature Conversions
Temperature conversions are unique because they involve an offset, not just a multiplier. The formulas are:
- Celsius to Fahrenheit: (°C × 9/5) + 32 = °F
- Fahrenheit to Celsius: (°F − 32) × 5/9 = °C
- Celsius to Kelvin: °C + 273.15 = K
Frequently Asked Questions
How do I convert km to miles?
Multiply kilometers by 0.621371 to get miles. For example, 10 km = 6.21 miles. This calculator does the conversion instantly.
How do I convert kg to pounds?
Multiply kilograms by 2.20462 to get pounds. For example, 10 kg = 22.05 lbs. Use the weight conversion category in this tool.
How to convert Celsius to Fahrenheit?
Use the formula: (Celsius × 9/5) + 32 = Fahrenheit. For example, 0°C = 32°F, and 100°C = 212°F.
What is the difference between metric and imperial units?
The metric system is decimal-based (powers of 10) and is used internationally. Imperial units (feet, miles, pounds) are traditional and still used in the United States and some other countries. Metric is generally easier for calculations due to its decimal nature.