Introduction
Temperature is measured using three main scales: Celsius, Fahrenheit, and Kelvin. Understanding how to convert between these scales is essential for cooking, science, and everyday life.
The Three Temperature Scales
Celsius (°C)
Celsius, also known as centigrade, is the most widely used temperature scale worldwide. It's based on the freezing and boiling points of water:
- 0°C = Freezing point of water
- 100°C = Boiling point of water
Used in: Most countries worldwide, scientific applications
Fahrenheit (°F)
Fahrenheit is primarily used in the United States. It was developed by Daniel Gabriel Fahrenheit in the early 18th century:
- 32°F = Freezing point of water
- 212°F = Boiling point of water
Used in: United States, some Caribbean countries
Kelvin (K)
Kelvin is the SI base unit for temperature, used primarily in scientific contexts. It's an absolute temperature scale starting from absolute zero:
- 0 K = Absolute zero (coldest possible temperature)
- 273.15 K = Freezing point of water
- 373.15 K = Boiling point of water
Used in: Scientific research, physics, chemistry
Conversion Formulas
Celsius to Fahrenheit
Formula: °F = (°C × 9/5) + 32
Example: Convert 25°C to Fahrenheit
- °F = (25 × 9/5) + 32
- °F = (45) + 32
- °F = 77
Fahrenheit to Celsius
Formula: °C = (°F - 32) × 5/9
Example: Convert 98.6°F to Celsius
- °C = (98.6 - 32) × 5/9
- °C = (66.6) × 5/9
- °C = 37
Celsius to Kelvin
Formula: K = °C + 273.15
Example: Convert 20°C to Kelvin
- K = 20 + 273.15
- K = 293.15
Kelvin to Celsius
Formula: °C = K - 273.15
Fahrenheit to Kelvin
Formula: K = (°F - 32) × 5/9 + 273.15
Quick Reference: Common Temperatures
| Description | Celsius | Fahrenheit | Kelvin |
|---|---|---|---|
| Absolute zero | -273.15°C | -459.67°F | 0 K |
| Freezing point of water | 0°C | 32°F | 273.15 K |
| Room temperature | 20-25°C | 68-77°F | 293-298 K |
| Body temperature | 37°C | 98.6°F | 310.15 K |
| Boiling point of water | 100°C | 212°F | 373.15 K |
Cooking Temperature Conversions
When cooking, accurate temperature conversions are crucial:
- Low heat: 200-250°F (93-121°C)
- Medium heat: 300-375°F (149-191°C)
- High heat: 400-450°F (204-232°C)
Oven Temperature Guide
- 250°F = 120°C (Very slow oven)
- 300°F = 150°C (Slow oven)
- 350°F = 175°C (Moderate oven)
- 400°F = 200°C (Hot oven)
- 450°F = 230°C (Very hot oven)
Tips for Temperature Conversion
- Use our free converter: For quick and accurate conversions
- Remember key reference points: Freezing (0°C/32°F) and boiling (100°C/212°F)
- For rough estimates: Double Celsius and add 30 to get approximate Fahrenheit
- For cooking: Use an oven thermometer to verify your oven's temperature
Why Different Scales Exist
Each temperature scale was developed for different reasons:
- Fahrenheit: Developed when thermometers were less accurate; 0°F was based on the coldest temperature Fahrenheit could achieve with a salt-ice mixture
- Celsius: Designed to be intuitive with water's freezing and boiling points as reference
- Kelvin: Created for scientific precision, starting from absolute zero where all molecular motion stops
Conclusion
Understanding temperature conversions is essential in our globalized world. Whether you're cooking, traveling, or working in science, being able to convert between Celsius, Fahrenheit, and Kelvin is a valuable skill. Use our temperature converter for instant, accurate conversions.