Unit Converter
Convert between length, weight, temperature, volume, area, speed, data storage, and time units — all in one tool.
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About this unit converter
Eight of the most commonly searched unit categories live in this one tool: length, weight, temperature, volume, area, speed, data storage, and time. Pick a category, choose the units you're converting between, and the tool handles the arithmetic instantly — no need to remember conversion factors or hunt down a category-specific calculator.
Temperature works differently from every other category here, which is why it gets its own explanation: Celsius, Fahrenheit, and Kelvin are not related by a simple multiplier the way kilometers and miles are. Converting between them involves both a scaling factor and an offset (Celsius to Fahrenheit is ×9/5 then +32, for example), so this tool calculates temperature conversions with dedicated formulas rather than the general unit-factor method used everywhere else. It also rejects any value below absolute zero (−273.15°C, 0 K), since that temperature is not physically possible.
Data storage carries a real ambiguity worth being upfront about: this converter uses the binary (1024-based) convention, where 1 kilobyte is 1,024 bytes and 1 gigabyte is 1,024 megabytes — matching how operating systems typically report file and drive sizes. Hard drive manufacturers and network speed figures, however, often use the decimal (1000-based) convention instead, which is why a drive labeled "1 TB" shows up as roughly 931 GB in your operating system. If you're working with manufacturer specifications rather than file sizes on disk, keep that distinction in mind.
Volume conversions use US customary units (US teaspoons, cups, gallons) rather than UK imperial measures for everything except the Imperial gallon, which is included separately since it's a genuinely different (larger) unit from the US gallon — a common source of recipe and fuel-economy confusion between the US and UK/Commonwealth countries.
Speed and time round out the set with their own small quirks worth flagging: knots (nautical miles per hour) are common in aviation and marine contexts but rarely elsewhere, and the "months" and "years" options in the time category use calendar averages (30.44 and 365.25 days respectively) rather than any specific real month or year, since actual month lengths vary between 28 and 31 days. For a precise duration spanning real calendar dates, the Days Between Dates calculator will give you an exact count instead of an average.
Every result is calculated in your browser; nothing you enter is sent anywhere.
Frequently asked questions
Why does temperature need special handling?
Celsius, Fahrenheit, and Kelvin scales don't share a common zero point, so converting between them requires an offset in addition to a scaling factor — unlike length or weight, where you just multiply by a fixed conversion factor.
Is a gigabyte 1000 megabytes or 1024 megabytes?
Both conventions exist. This tool uses 1,024 (the binary convention operating systems use for file sizes). Drive manufacturers and network speeds commonly use 1,000 instead, which is why a "1 TB" drive shows less than 1,024 GB of usable space in your file explorer.
What's the difference between a US gallon and an Imperial gallon?
An Imperial (UK) gallon is about 20% larger than a US gallon — 4.546 liters versus 3.785 liters. Both are included here as separate units since mixing them up is a common source of error in recipes and fuel economy figures.
Can I convert a temperature below absolute zero?
No. The calculator blocks any input that would correspond to a temperature colder than absolute zero (−273.15°C or 0 K), since that is not physically possible.
How precise are the conversion results?
Results are calculated using standard internationally recognized conversion factors and shown to up to 6 decimal places, which is more than enough precision for everyday, cooking, travel, or DIY use.