Why unit conversion matters
Recipes, travel, DIY, and product specs often mix metric (metres, kilograms, Celsius) and imperial or US customary (feet, pounds, Fahrenheit). Converting between them avoids errors and helps you compare options.
The key is knowing the conversion factor: one unit equals how many of the other? From there you multiply or divide.
Length and distance
Common conversions: 1 inch = 2.54 cm (exact). 1 foot = 12 inches = 0.3048 m. 1 mile = 1.609 km. So 5 miles ≈ 8.05 km, and 100 m ≈ 328 feet.
Use a length converter when you’re switching between metres, centimetres, feet, inches, yards, miles, or millimetres. Enter the value and the “from” and “to” units; the result updates instantly.
- 1 m ≈ 3.28 ft
- 1 km ≈ 0.62 mi
- 1 in = 2.54 cm
Weight and mass
In everyday use, “weight” and “mass” are often used interchangeably. 1 kg ≈ 2.205 lb. So 70 kg ≈ 154 lb. For cooking or shipping, a weight converter handles grams, kilograms, ounces, and pounds quickly.
Temperature
Celsius to Fahrenheit: F = (C × 9/5) + 32. So 20°C = 68°F. Fahrenheit to Celsius: C = (F − 32) × 5/9. So 98.6°F ≈ 37°C. Freezing is 0°C (32°F); boiling at sea level is 100°C (212°F).
A temperature converter is handy for weather, recipes, or science. Enter a value and choose the units; you get the result in the other scale.
Other units
We also offer converters for area, volume, speed, pressure, power, time, and data (bytes/bits). The same idea applies: pick “from” and “to” units, enter the value, and read the result. All use standard definitions so conversions are consistent.
Tools to use
Use our Length Converter for distance, Weight & Mass Converter for kg/lb and similar, and Temperature Converter for °C and °F. Browse the Unit Converters category for the full set. Everything runs in your browser.