Unit Converters
Convert common metric and imperial units for length, weight, temperature, area, volume, and speed.
Popular unit converter pages
This unit converter cluster is built around specific everyday conversions rather than only a generic calculator. Use the length converter for cm to inches, inches to cm, mm to inches, feet to meters, meters to feet, km to miles, and miles to km. Use the weight converter for kg to lbs, lbs to kg, grams to ounces, and ounces to grams. Use the temperature converter for Celsius to Fahrenheit, Fahrenheit to Celsius, Celsius to Kelvin, and Kelvin to Celsius.
Common conversion searches
- cm to inches and inches to cm for dimensions, clothing, and product specs.
- kg to lbs and lbs to kg for body weight, shipping, gym weights, and packages.
- Celsius to Fahrenheit and Fahrenheit to Celsius for weather, cooking, HVAC, and science.
- Feet to meters, meters to feet, km to miles, and miles to km for travel and construction.
- Square feet to square meters, liters to gallons, mph to km/h, and knots to mph.
Available tools
7 results
Metric and imperial conversion formulas
Most unit conversions use a fixed factor: multiply by the source unit's base-unit factor, then divide by the target unit's factor. Temperature conversions are different because Celsius, Fahrenheit, and Kelvin have offsets as well as scale differences.
The individual converter pages include popular conversion sections and formula notes for exact queries such as cm to inches, kg to lbs, grams to ounces, Celsius to Fahrenheit, liters to gallons, and mph to km/h.
Unit converter FAQ
Are the conversion factors exact?
Many metric-imperial factors used here are exact definitions, such as 1 inch = 2.54 centimeters and 1 pound = 0.45359237 kilograms. Results are rounded for display.
Why are temperature conversions different?
Temperature scales use offsets. For example, Fahrenheit to Celsius subtracts 32 before multiplying by 5/9, while Celsius to Fahrenheit multiplies by 9/5 and adds 32.