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~6 min readHow to Convert Units Online
Unit conversions come up constantly — a recipe in cups versus grams, a distance in miles versus kilometres, a product weight in pounds versus kilograms for an international shipping form. Browser-based converters give you the answer immediately without calculations or looking up formulas.
How to convert length units
Open the Length Converter, enter a value, and all equivalent values in other units appear simultaneously. Common length conversions:
- 1 metre = 3.281 feet = 39.37 inches = 100 centimetres
- 1 kilometre = 0.621 miles = 1,000 metres
- 1 mile = 1.609 kilometres = 5,280 feet
- 1 inch = 2.54 centimetres
- 1 foot = 30.48 centimetres
Length conversions matter for international shipping dimensions (couriers often specify limits in both units), construction plans that switch between metric and imperial, and athletic events (5K and 10K races are often listed alongside their mile equivalents).
How to convert weight units
The Weight Converter handles the units used in everyday life, cooking, fitness, and shipping. Key conversions:
- 1 kilogram = 2.205 pounds = 35.27 ounces
- 1 pound = 0.454 kilograms = 16 ounces
- 1 stone = 14 pounds = 6.35 kilograms (used for body weight in the UK)
- 1 metric tonne = 1,000 kilograms = 2,205 pounds
Cooking is the most common everyday context for weight conversion. US recipes list ingredients in cups and ounces; UK and European recipes use grams. Baking in particular benefits from precise measurements — a cup of flour can weigh anywhere from 120g to 160g depending on how it is packed, so grams are more reliable.
How to convert temperatures
The Temperature Converter converts between Celsius, Fahrenheit, and Kelvin. The formulas are:
- °F to °C: subtract 32, then multiply by 5/9
- °C to °F: multiply by 9/5, then add 32
- °C to K: add 273.15
- K to °C: subtract 273.15
Useful reference temperatures: 0°C / 32°F (water freezes), 100°C / 212°F (water boils), 37°C / 98.6°F (normal body temperature), 180°C / 356°F (a common baking temperature), 200°C / 392°F (another common oven temperature).
Number system conversions: Binary, Decimal, and Hex
For technical work, the converter tools also cover number system conversions:
- The Binary to Decimal Converter translates base-2 binary strings to base-10 decimal numbers.
- The Decimal to Binary Converter goes the other direction.
- The Hex to RGB Converter and RGB to Hex Converter handle color value conversions used in design and web development.
Browse the complete set on the Converter Tools category page.
How to Convert Units Online FAQs
Are unit conversions accurate?
Yes. The converters use standard conversion factors (metres to feet, Celsius to Fahrenheit, etc.) that match official definitions. Results are accurate to several decimal places — more precision than most practical applications require.
Can I convert between metric and imperial in both directions?
Yes. Enter a value in any unit field and all the equivalent values update simultaneously. You can enter miles and read kilometres, or enter kilograms and read pounds and stones at the same time.
Why do some recipes use volume measurements and others use weight?
US recipes traditionally use volume (cups, tablespoons, teaspoons) for convenience. UK and European recipes use weight (grams, kilograms) for precision. Weight is generally more accurate for baking because the density of dry ingredients varies with how they are packed.
What is Kelvin used for?
Kelvin is the SI unit of temperature used in scientific contexts, particularly in physics, chemistry, and astronomy. 0 K (absolute zero) is the coldest possible temperature. Unlike Celsius and Fahrenheit, Kelvin has no negative values — absolute zero is the floor.
Related tools
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