Unit Converter
Convert between units of length, weight, temperature, data size, speed, and more instantly in your browser.
About This Tool
The Unit Converter is a free browser-based tool that lets you convert between a wide range of measurement units across eight categories: length, weight, temperature, data size, speed, time, area, and volume. Whether you are a developer calculating data transfer sizes, an engineer working with metric and imperial measurements, or just figuring out how many cups are in a gallon, this tool handles it all instantly.
Unlike many online converters, this tool runs entirely in your browser. No data is sent to any server, no accounts are needed, and no ads interrupt your workflow. Every conversion is performed using precise JavaScript arithmetic, so you get accurate results every time.
The converter supports bidirectional conversion: enter a value in either the source or target field and the other updates instantly. The swap button lets you reverse the direction with a single click. For each conversion, a full table of all units in the same category is displayed, giving you a comprehensive view of how your value translates across every supported unit.
Temperature conversions use the standard formulas for Celsius, Fahrenheit, and Kelvin, while all other categories use ratio-based conversion through a common base unit. Data sizes use binary prefixes (1 KB = 1024 bytes) to match how operating systems and programming languages report storage. If you work with CSS units frequently, you may also find the px-rem converter useful, and for numeric base conversions check out the number base converter. For mathematical calculations, try the math expression evaluator.
How to Use
- Select a category tab at the top (Length, Weight, Temperature, Data Size, Speed, Time, Area, or Volume).
- Enter a numeric value in the From input field.
- Choose the source unit from the dropdown below the input.
- Choose the target unit from the dropdown on the right side.
- The converted result appears instantly in the To field. Click the copy icon to copy it.
- Use the swap button (arrows) between the two panels to reverse the conversion direction.
- Scroll down to the All Conversions table to see the value converted to every unit in the category. Click any row to copy.
- Keyboard shortcut: Ctrl+Shift+C copies the current conversion result to your clipboard.
Popular Unit Conversion Examples
FAQ
Is my data safe?
Yes. All conversions are performed entirely in your browser using JavaScript arithmetic. No data is sent to any server, no cookies are set, and no third-party scripts are involved.
Does 1 KB equal 1000 or 1024 bytes?
This tool uses binary prefixes where 1 KB = 1024 bytes, 1 MB = 1,048,576 bytes, and so on. This matches how most operating systems and programming languages report file sizes. The SI standard (1 KB = 1000 bytes) uses different prefixes (kB) but is less common in software development contexts.
How accurate are the conversions?
All conversions use IEEE 754 double-precision floating-point arithmetic, which provides approximately 15-17 significant decimal digits of precision. Results are displayed with up to 10 significant digits. For most practical purposes this exceeds the accuracy needed.
Which temperature scales are supported?
The tool supports Celsius, Fahrenheit, and Kelvin. Conversions use the standard formulas: F = C x 9/5 + 32, K = C + 273.15. All three scales are bidirectionally convertible.
Can I convert between metric and imperial units?
Yes. Every category includes both metric and imperial units where applicable. For example, Length includes both metric (mm, cm, m, km) and imperial (in, ft, yd, mi) units. Weight includes grams, kilograms, pounds, and ounces.
What year length is used for time conversions?
Time conversions use the Julian year of exactly 365.25 days (31,557,600 seconds), which is the standard used in astronomy and science. This accounts for leap years on average.
Are US or Imperial gallons used for volume?
The volume conversions use US customary units. One US gallon equals approximately 3.785 liters. If you need Imperial (UK) gallons, multiply the US gallon value by approximately 1.201.
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