How to Convert Celsius, Fahrenheit & Kelvin

Understanding Temperature Scales

Temperature is one of the most commonly converted measurements, yet it's also one of the trickiest because it doesn't use simple multiplication like other unit conversions.

The Three Main Scales

Celsius (°C)

• Freezing point of water: 0°C
• Boiling point of water: 100°C
• Used by: Most of the world
• Best for: Daily weather, cooking, science

Fahrenheit (°F)

• Freezing point of water: 32°F
• Boiling point of water: 212°F
• Used by: United States, some Caribbean nations
• Best for: Weather in the US, some cooking

Kelvin (K)

• Absolute zero: 0 K (-273.15°C)
• Freezing point of water: 273.15 K
• Used by: Scientists worldwide
• Best for: Scientific calculations, physics

Conversion Formulas

Celsius to Fahrenheit

°F = (°C × 9/5) + 32

Fahrenheit to Celsius

°C = (°F - 32) × 5/9

Celsius to Kelvin

K = °C + 273.15

Kelvin to Celsius

°C = K - 273.15

Quick Reference Points

Practical Examples

Example 1: Convert 25°C to Fahrenheit

°F = (25 × 9/5) + 32 = 45 + 32 = 77°F

Example 2: Convert 98.6°F to Celsius

°C = (98.6 - 32) × 5/9 = 66.6 × 5/9 = 37°C

Key Takeaways

• Temperature conversions require formulas, not simple multiplication
• Celsius and Kelvin differ by exactly 273.15
• Fahrenheit uses a different scale entirely
• Room temperature is about 20°C, 68°F, or 293K