Unit Converter
Convert length, weight, temperature, volume, speed and data units.
Common equivalents
How do you convert units of measurement online?
Docuboxer's unit converter switches instantly between length, mass, temperature, area, volume, speed, time and digital data: pick a category, search for the source and target unit by name or symbol, and type a value into either field — the conversion updates live in both directions, no button required. It covers metric units (meters, kilograms, liters) alongside the most-searched imperial and US customary units — inches, feet, miles, pounds, ounces, gallons — and correctly separates the US gallon from the UK imperial gallon, which aren't the same size despite sharing a name. Temperature uses the actual formula for each scale, since Celsius, Fahrenheit, Kelvin and Rankine don't share a zero point, and digital storage keeps decimal prefixes (kB = 1000 bytes) distinct from binary ones (KiB = 1024 bytes). Every conversion also shows equivalent values in the category's most common units. Everything runs in your browser, it's free, and no signup is required.
How to use Unit Converter
- Pick the unit category you need: length, mass, temperature, area, volume, speed, time or digital data.
- Choose the source and target unit from the dropdowns, or search for either one by name or symbol.
- Type the value you want to convert into either field — the other one updates instantly, in both directions.
- Use the swap button to instantly reverse the conversion direction without re-selecting units.
- Copy the result with one click, or check the common equivalents panel to see the value in several units at once.
Common use cases
Converting recipe measurements to metric
Turn cups, teaspoons and ounces from a US recipe into milliliters and grams to cook with metric measurements without ruining the proportions.
Translating travel distances and road signs
Convert miles to kilometers and feet to meters when planning a trip or reading road signs in a country that uses the metric system.
Converting your weight or height to another unit
Convert pounds to kilograms or feet and inches to centimeters for medical forms, fitness apps, or paperwork abroad.
Checking the real size of a file or drive
Work out whether a manufacturer is advertising a drive's capacity in GB (decimal) or your OS is showing it in GiB (binary), and understand why the numbers don't match.
Converting temperatures between scales
Turn a Fahrenheit thermometer reading into Celsius, or the other way around, for a recipe, a weather forecast, or a foreign technical spec.
Frequently asked questions
How do I convert inches to cm?
One inch equals exactly 2.54 centimeters. Type the value into the inches field and the centimeter result appears instantly — no manual math needed.
How do I convert pounds to kilograms?
One pound equals 0.45359237 kilograms. Pick the Mass/Weight category, set pounds as the source unit and kilograms as the target, then type the value you want to convert.
How many kilometers are in a mile?
One mile equals 1.609344 kilometers. It's one of the most common conversions when planning a road trip in a country that measures distance in kilometers instead of miles.
How do I convert Fahrenheit to Celsius?
The formula is °C = (°F − 32) × 5/9. The converter applies it automatically: choose Temperature, set Fahrenheit as the source and Celsius as the target, and type the value.
Why isn't a US gallon the same as a UK gallon?
They're historically different units: the US gallon equals 3.785411784 liters, while the UK imperial gallon equals 4.54609 liters — almost 20% more. The converter treats them as separate units so you don't mix them up.
What's the difference between kB and KiB?
kB (kilobyte) uses the decimal SI prefix and equals 1000 bytes; KiB (kibibyte) uses the binary prefix and equals 1024 bytes. Operating systems often display file sizes in binary units while labeling them as if they were decimal, which is why a "1 GB" file sometimes looks smaller than expected.