Unit Converter
Select conversion category and enter value to convert
Common Unit Facts
• 1 inch = 2.54 centimeters (exact conversion)
• Water freezes at 0°C (32°F) and boils at 100°C (212°F)
• 1 kilogram = 2.20462 pounds
• 1 mile = 1.60934 kilometers
• 1 liter = 0.264172 gallons
Detailed Conversion
Other Common Conversions
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Select conversion category, enter a value, and choose units to see instant conversion results.
Common Conversion Tables
Length Conversions
| Unit | Equals | In Meters | Common Uses |
|---|---|---|---|
| 1 inch | 2.54 cm | 0.0254 m | Screen sizes, height |
| 1 foot | 12 inches | 0.3048 m | Room dimensions |
| 1 yard | 3 feet | 0.9144 m | Fabric, football |
| 1 mile | 1.609 km | 1609.34 m | Road distances |
| 1 kilometer | 0.621 miles | 1000 m | Running, driving |
Weight Conversions
| Unit | Equals | In Kilograms | Common Uses |
|---|---|---|---|
| 1 ounce | 28.35 grams | 0.02835 kg | Food, mail |
| 1 pound | 16 ounces | 0.4536 kg | Body weight |
| 1 stone | 14 pounds | 6.35 kg | UK body weight |
| 1 metric ton | 1000 kg | 1000 kg | Shipping, industry |
Temperature Conversions
| Celsius (°C) | Fahrenheit (°F) | Kelvin (K) | Description |
|---|---|---|---|
| -40°C | -40°F | 233.15 K | Extreme cold |
| 0°C | 32°F | 273.15 K | Water freezes |
| 20°C | 68°F | 293.15 K | Room temperature |
| 37°C | 98.6°F | 310.15 K | Human body |
| 100°C | 212°F | 373.15 K | Water boils |
Conversion Formulas
- • Temperature: °F = (°C × 9/5) + 32 | °C = (°F - 32) × 5/9
- • Length: 1 inch = 2.54 cm (exact) | 1 mile = 1.609344 km (exact)
- • Weight: 1 kg = 2.20462262185 lbs | 1 lb = 0.45359237 kg
- • Volume: 1 liter = 0.264172 gallons | 1 gallon = 3.78541 liters
Frequently Asked Questions
Our unit converter uses precise conversion factors with high accuracy:
Accuracy Levels:
- • Scientific accuracy: Uses NIST (National Institute of Standards and Technology) standard values
- • Decimal precision: Calculations up to 15 decimal places
- • International standards: Follows SI (International System of Units) definitions
- • Real-time precision: No rounding until final display
For most everyday use, the conversions are more than accurate enough. For scientific or engineering purposes, we recommend verifying critical conversions with authoritative sources.
Different measurement systems developed historically in different regions:
The metric system (International System of Units) is the modern standard used worldwide for science, medicine, and most international trade. The imperial system persists in the United States for everyday measurements. Some specialized fields also use their own units (like computer storage in bytes).
While often used interchangeably in everyday language, mass and weight are scientifically different:
Mass
- • Amount of matter in an object
- • Constant everywhere in the universe
- • Measured in kilograms (kg)
- • Doesn't change with location
- • Measured with balances
Weight
- • Force of gravity on an object
- • Changes with location/gravity
- • Measured in newtons (N)
- • Less on Moon, zero in space
- • Measured with scales
In everyday conversions, we use "weight" to mean mass, as scales are calibrated for Earth's gravity. For scientific accuracy, the distinction is important.
Here are some quick mental conversion tricks:
Quick Approximation Formulas:
°C to °F:
Double it, subtract 10%, add 32
Example: 20°C → 40 - 4 + 32 = 68°F
°F to °C:
Subtract 32, halve it, add 10%
Example: 68°F → (36 ÷ 2) + 3.6 = 18 + 3.6 = 21.6°C
Memorable reference points:
- • 0°C = 32°F (freezing point of water)
- • 10°C = 50°F (cool day)
- • 20°C = 68°F (room temperature)
- • 30°C = 86°F (warm day)
- • 37°C = 98.6°F (body temperature)
- • 100°C = 212°F (boiling point of water)
Based on usage statistics, these are the most frequently needed conversions: