Free Unit Converter - Length, Weight, Temperature, Volume
Free online unit converter tool. Convert length (meters, feet, inches), weight (kg, lbs, ounces), temperature (Celsius, Fahrenheit, Kelvin), volume (liters, gallons, cups), and more. Instant, accurate conversions with detailed formulas and examples.
Why Use Our Unit Converter?
Our Free Unit Converter is the most comprehensive and accurate conversion tool available online. Whether you need to convert length measurements for construction, weight for cooking recipes, temperature for science experiments, or volume for beverage measurements, our tool provides instant, precise conversions between metric and imperial units.
Perfect for students solving physics problems, engineers working on international projects, cooks adapting recipes, travelers understanding foreign measurements, healthcare professionals calculating dosages, and anyone who needs quick, reliable unit conversions. No installation required, works on any device, and provides results with 6 decimal places of precision.
Convert between dozens of units including meters, feet, kilometers, miles, kilograms, pounds, Celsius, Fahrenheit, liters, gallons, and many more. All conversions use internationally recognized standards and are mathematically accurate.
Supported Unit Categories
📏 Length / Distance
- Metric: Meters (m), Kilometers (km), Centimeters (cm), Millimeters (mm)
- Imperial: Feet (ft), Miles (mi), Yards (yd), Inches (in)
- Common Uses: Construction, travel distances, height measurements, fabric length
⚖️ Weight / Mass
- Metric: Kilograms (kg), Grams (g), Milligrams (mg), Metric Tons
- Imperial: Pounds (lbs), Ounces (oz), Tons (US), Stones
- Common Uses: Cooking, body weight, shipping, science experiments
🌡️ Temperature
- Scales: Celsius (°C), Fahrenheit (°F), Kelvin (K)
- Common Uses: Weather, cooking, science, medical temperature, oven settings
- Key Points: Water freezes at 0°C/32°F, boils at 100°C/212°F
💧 Volume / Capacity
- Metric: Liters (L), Milliliters (mL), Cubic Meters (m³)
- Imperial: Gallons (gal), Fluid Ounces (fl oz), Cups, Pints, Quarts
- Common Uses: Cooking, beverages, fuel, liquid measurements
Key Features
- Instant Conversion: Results appear in real-time as you type
- Multiple Categories: Length, weight, temperature, and volume conversions
- High Precision: Accurate to 6 decimal places for precise calculations
- Bidirectional: Convert in both directions (metric ↔ imperial)
- Common Units: Includes all frequently used measurement units
- No Registration: Use instantly without creating an account
- 100% Free: All conversions available at no cost
- Mobile-Friendly: Works perfectly on smartphones, tablets, and computers
- Privacy-Focused: All calculations happen in your browser
- Easy to Use: Simple, intuitive interface for quick conversions
How to Use the Unit Converter
- Select Category: Choose Length, Weight, Temperature, or Volume
- Enter Your Value: Type the number you want to convert
- Select From Unit: Choose the unit you're converting FROM
- Select To Unit: Choose the unit you're converting TO
- View Result: The converted value appears instantly with high precision
Common Conversion Examples
📏 Length Conversions
- • 1 meter = 3.28084 feet = 39.3701 inches
- • 1 kilometer = 0.621371 miles = 3,280.84 feet
- • 1 inch = 2.54 centimeters
- • 1 mile = 1.60934 kilometers = 5,280 feet
⚖️ Weight Conversions
- • 1 kilogram = 2.20462 pounds = 35.274 ounces
- • 1 pound = 0.453592 kilograms = 16 ounces
- • 1 gram = 0.035274 ounces
- • 1 ton (metric) = 1,000 kilograms = 2,204.62 pounds
🌡️ Temperature Conversions
- • 0°C = 32°F = 273.15 K (water freezing point)
- • 100°C = 212°F = 373.15 K (water boiling point)
- • 25°C = 77°F (room temperature)
- • -40°C = -40°F (same in both scales)
💧 Volume Conversions
- • 1 liter = 0.264172 gallons (US) = 33.814 fluid ounces
- • 1 gallon (US) = 3.78541 liters = 16 cups
- • 1 cup = 236.588 milliliters = 8 fluid ounces
- • 1 milliliter = 0.033814 fluid ounces
Common Use Cases
👨🍳 Cooking & Baking
Convert recipe measurements when using international cookbooks. Switch between cups, milliliters, ounces, grams, Fahrenheit, and Celsius for perfect results every time.
🎓 Education & Homework
Solve physics, chemistry, and math problems. Convert units for science experiments, engineering calculations, and academic assignments with precision.
🏗️ Construction & Engineering
Convert blueprints and measurements between metric and imperial systems. Essential for international projects, material calculations, and precise building specifications.
✈️ Travel & Tourism
Understand foreign measurements while traveling. Convert speed limits (km/h to mph), distances, temperatures, and weights to familiar units.
🏋️ Fitness & Health
Track body weight in different units, convert exercise distances (miles to kilometers), understand nutrition labels, and monitor health metrics.
🚗 Automotive & Fuel
Convert fuel efficiency (MPG to L/100km), tire pressure (PSI to bar), and understand international vehicle specifications.
📦 Shipping & Logistics
Calculate package weights and dimensions in required units. Convert between different measurement systems for international shipping requirements.
🔬 Science & Research
Perform laboratory calculations, convert experimental data, and ensure accuracy in scientific measurements across different unit systems.
Understanding Metric vs Imperial Systems
Metric System (SI Units)
The metric system, also known as the International System of Units (SI), is based on powers of 10, making calculations easier:
- Base Units: Meter (length), Kilogram (mass), Liter (volume), Celsius (temperature)
- Prefixes: kilo- (1,000), centi- (0.01), milli- (0.001), etc.
- Used By: Almost all countries worldwide, scientific community, international trade
- Benefits: Easier calculations, consistent conversions, universal standard
Imperial System (US Customary Units)
The imperial system uses historical units still common in the United States and some other countries:
- Base Units: Foot (length), Pound (mass), Gallon (volume), Fahrenheit (temperature)
- Conversions: Often irregular (12 inches = 1 foot, 16 ounces = 1 pound)
- Used By: United States, limited use in UK and some Commonwealth countries
- History: Based on traditional British measurements from before metrication
Why Convert Between Systems?
- International Collaboration: Working with teams in different countries
- Product Specifications: Understanding measurements from different regions
- Education: Learning both systems for comprehensive understanding
- Daily Life: Traveling, cooking with international recipes, online shopping
Conversion Formulas
Temperature Formulas:
- • °F = (°C × 9/5) + 32
- • °C = (°F - 32) × 5/9
- • K = °C + 273.15
- • °C = K - 273.15
Length Formulas:
- • feet = meters × 3.28084
- • meters = feet × 0.3048
- • inches = centimeters × 0.393701
- • miles = kilometers × 0.621371
Weight Formulas:
- • pounds = kilograms × 2.20462
- • kilograms = pounds × 0.453592
- • ounces = grams × 0.035274
- • grams = ounces × 28.3495
Volume Formulas:
- • gallons = liters × 0.264172
- • liters = gallons × 3.78541
- • fluid ounces = milliliters × 0.033814
- • milliliters = fluid ounces × 29.5735
Frequently Asked Questions (FAQ)
How do I convert units using this tool?
Select the unit category (length, weight, temperature, or volume), enter your value, choose the 'from' unit and 'to' unit, and the conversion result appears instantly. The tool handles all calculations automatically with high precision.
How do you convert Celsius to Fahrenheit?
To convert Celsius to Fahrenheit, multiply the Celsius temperature by 9/5 (or 1.8) and add 32. Formula: °F = (°C × 9/5) + 32. For example, 25°C = (25 × 1.8) + 32 = 77°F. Our converter does this calculation automatically.
How many feet are in a meter?
1 meter equals 3.28084 feet. To convert meters to feet, multiply by 3.28084. To convert feet to meters, divide by 3.28084 (or multiply by 0.3048). Our unit converter provides instant, accurate conversions between these and many other length units.
How many pounds are in a kilogram?
1 kilogram equals 2.20462 pounds. To convert kg to lbs, multiply by 2.20462. To convert lbs to kg, divide by 2.20462 (or multiply by 0.453592). This is the standard conversion used worldwide.
What's the difference between metric and imperial units?
Metric units (meters, kilograms, liters) are based on powers of 10 and used worldwide. Imperial units (feet, pounds, gallons) are primarily used in the United States. Metric is generally easier for calculations, while imperial persists in some countries due to historical usage.
Is this unit converter accurate?
Yes! Our converter uses internationally recognized conversion factors and provides results with 6 decimal places of precision. All conversions are mathematically accurate and follow standards from organizations like NIST (National Institute of Standards and Technology).
Why are there different types of gallons?
There are two main types: US gallon (3.785 liters) and UK (imperial) gallon (4.546 liters). The difference stems from different historical definitions. Our converter specifies which gallon type is being used to avoid confusion.
How do I convert cooking measurements?
For cooking, use the volume converter for liquids (cups, tablespoons, milliliters) and the weight converter for dry ingredients (grams, ounces). Note that weight is more accurate than volume for baking, as volume can vary with packing density.
What temperature should I use for baking?
Most US recipes use Fahrenheit, while international recipes use Celsius. Common baking temperatures: 350°F = 175°C (standard), 375°F = 190°C, 400°F = 200°C, 425°F = 220°C. Use our temperature converter for exact conversions.
Can I convert between different types of units?
No, you can only convert within the same category (length to length, weight to weight, etc.). You cannot convert length to weight or temperature to volume, as these measure different physical properties.
Why do I need to convert units?
Unit conversion is essential for international communication, scientific work, cooking with international recipes, traveling abroad, understanding product specifications, academic homework, professional engineering, and countless daily situations where different measurement systems are used.
Tips for Accurate Conversions
- ✓ Use appropriate precision: More decimal places don't always mean more accuracy in practical applications
- ✓ Know your context: Cooking requires less precision than engineering or scientific work
- ✓ Double-check critical conversions: Verify important calculations, especially for safety-critical applications
- ✓ Understand significant figures: Don't claim more precision than your input provides
- ✓ Be aware of rounding: Multiple conversions can accumulate rounding errors
- ✓ Use weight for baking: Weight is more accurate than volume for dry ingredients
- ✓ Check gallon type: Specify US or UK gallons to avoid confusion
- ✓ Remember absolute zero: -273.15°C = 0 K (nothing is colder)
- ✓ Keep reference conversions: Memorize common ones like 1 inch = 2.54 cm exactly
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