Unit Converter
Convert between 200+ measurement units across 10+ categories including length, weight, temperature, area, volume, speed, time, and data storage.
Select Conversion Category
Length Conversion
Conversion Formula
Common Conversions
Recent Conversions
Unit Reference
Measurement Systems
Metric System
Used worldwide, based on powers of 10
Imperial System
Used in the United States
US Customary
Similar to Imperial but with some differences
Popular Conversions
Conversion Tips
- Use decimals for precise conversions
- Check your unit system (Metric/Imperial)
- Temperature formulas are different from linear conversions
What is a Unit Converter?
A unit converter is an essential tool that transforms measurements from one unit to another within the same quantity. Whether you're converting meters to feet, kilograms to pounds, Celsius to Fahrenheit, or bytes to gigabytes, unit converters eliminate mathematical errors and save time by providing instant, accurate conversions between different measurement systems.
Our online unit converter supports over 200 units across 10+ measurement categories, making it one of the most comprehensive conversion tools available. It's particularly valuable for international work, scientific research, engineering projects, cooking, travel planning, and everyday problem-solving where different measurement systems are used.
How to Use This Unit Converter
This intuitive unit converter is designed for simplicity and accuracy. Follow these steps for seamless conversions:
- Select a Category: Choose from length, weight, temperature, area, volume, speed, time, data storage, pressure, or energy conversion.
- Enter Your Value: Type the numerical value you want to convert in the "Convert From" field.
- Select Units: Choose the source unit (what you're converting from) and the target unit (what you're converting to) from the dropdown menus.
- Convert: Click "Convert Now" or simply change any value to see instant results. Use the "Swap Units" button to reverse the conversion direction.
- Quick Conversions: Use the common conversion buttons for frequently needed conversions.
- History: All your conversions are saved in the history section for easy reference and reuse.
Why Use This Online Unit Converter?
This converter offers significant advantages over manual calculations, physical conversion charts, and basic conversion tools:
Comprehensive Coverage
200+ units across 10+ categories including specialized units for engineering, science, cooking, and everyday use. From nanometers to light-years, milligrams to tons, we've got you covered.
Instant Results
Real-time conversion as you type. No need to press "calculate" – see results immediately when you change values or units. Perfect for comparing multiple units quickly.
Conversion History
Automatic tracking of all your conversions with ability to reuse previous values. Never lose an important conversion again.
Mobile-Friendly
Fully responsive design that works perfectly on smartphones, tablets, and desktops. Convert units anywhere, anytime without downloading an app.
Who Should Use This Unit Converter?
| User Group | Common Uses | Most Used Conversions |
|---|---|---|
| Students | Homework, science projects, international studies | Metric to Imperial, temperature, scientific units |
| Engineers & Scientists | Technical drawings, research data, international collaboration | SI units, pressure, energy, specialized measurements |
| Cooks & Bakers | Following international recipes, scaling ingredients | Volume, weight, temperature (oven settings) |
| Travelers | Understanding local measurements, distance, temperature | Kilometers to miles, Celsius to Fahrenheit, currency (if available) |
| Professionals | International business, construction, manufacturing | Area, volume, length, weight for materials |
Understanding Measurement Systems
Metric System (International System of Units - SI)
Base Units
Meter (length), Kilogram (mass), Second (time), Ampere (current), Kelvin (temperature), Mole (amount), Candela (luminous intensity)
Prefix System
Based on powers of 10: kilo- (1000), centi- (1/100), milli- (1/1000), micro- (1/1,000,000)
Used by all countries except the United States, Liberia, and Myanmar. Adopted for scientific work worldwide due to its decimal-based simplicity and consistency.
Imperial System
Common Units
Inch, foot, yard, mile (length); Ounce, pound, stone (weight); Fluid ounce, pint, gallon (volume)
Characteristics
Based on historical precedents, not decimal system. Conversion factors are often irregular (e.g., 12 inches = 1 foot, 3 feet = 1 yard)
Primarily used in the United States. Originated from British imperial units but with some differences in volume measurements.
Special Conversion Cases
Temperature Conversions
Unlike linear conversions (where you multiply by a constant factor), temperature conversions require specific formulas:
°C to °F: (°C × 9/5) + 32
Celsius to Fahrenheit
°F to °C: (°F - 32) × 5/9
Fahrenheit to Celsius
K to °C: K - 273.15
Kelvin to Celsius
°C to K: °C + 273.15
Celsius to Kelvin
Data Storage Conversions
Data storage uses binary prefixes (powers of 2) but is often confused with decimal prefixes (powers of 10):
1 Kilobyte (KB) = 1024 Bytes
Binary system (2^10)
1 Megabyte (MB) = 1024 KB
Binary system (2^20)
1 Kibibyte (KiB) = 1024 Bytes
Official binary prefix
1 Kilobyte (KB) = 1000 Bytes
Decimal system (marketing)
Frequently Asked Questions (FAQ)
Why are temperature conversions different from other conversions?
Temperature scales have different zero points and scale intervals. Celsius and Fahrenheit both set their zero points arbitrarily (freezing point of water for Celsius, a brine solution for Fahrenheit), while Kelvin uses absolute zero. This means temperature conversion requires both scaling AND offset adjustments, unlike linear conversions which only need scaling. For example, 0°C = 32°F, not 0°F.
How accurate are the conversions?
Conversions use precise mathematical formulas and conversion factors with up to 14 decimal places of accuracy. For standard conversions, results are accurate to at least 8 significant figures. However, it's important to note that some conversions (like those involving historical units) may have slight variations in definitions. For scientific work requiring extreme precision, always verify conversion factors against authoritative sources.
What's the difference between US and Imperial gallons?
The US gallon and Imperial (UK) gallon are different volumes: 1 US gallon = 3.78541 liters, while 1 Imperial gallon = 4.54609 liters. This difference dates back to 1824 when Britain redefined the gallon. The US continued using the older wine gallon. When converting between gallons and liters, always specify which gallon you're using. Our converter distinguishes between these two units.
How do I convert between metric prefixes (e.g., mm to km)?
Metric prefixes represent powers of 10. To convert between prefixes directly: 1 kilometer = 1,000 meters = 1,000,000 millimeters. Our converter handles these automatically. For example, converting 5,000 mm to km: Instead of converting mm → m → km manually, simply select "millimeter" as the source unit and "kilometer" as the target unit. The converter applies the 10^6 factor automatically (5,000 mm = 0.005 km).
Can I convert currencies with this tool?
This specific tool focuses on physical measurement units (length, weight, volume, etc.). For currency conversion, we recommend using our dedicated Currency Converter which includes real-time exchange rates. Currency conversion requires live data feeds as exchange rates change constantly, while measurement unit conversions use fixed mathematical relationships.
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