Celsius vs Fahrenheit

Celsius and Fahrenheit are the two most common temperature scales. Most of the world uses Celsius, while the United States primarily uses Fahrenheit. Understanding the conversion between them is essential for cooking, weather, science, and travel.

Celsius (°C)

Celsius is the metric temperature scale used by most countries. It's based on the freezing (0°C) and boiling (100°C) points of water.

  • Used by most countries worldwide
  • Water freezes at 0°C, boils at 100°C
  • Used in science universally
  • Metric system (base-10 friendly)
Best for: International communication, science, and countries using the metric system.
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Fahrenheit (°F)

Fahrenheit is primarily used in the United States. It has finer granularity for weather temperatures since each degree is smaller.

  • Used primarily in the United States
  • Water freezes at 32°F, boils at 212°F
  • More precise for weather (0-100°F covers common range)
  • 180 degrees between freezing and boiling
Best for: Weather reporting in the US, cooking with American recipes, and everyday temperature in the US.
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Key Differences

AspectCelsius (°C)Fahrenheit (°F)
Water Freezes0°C32°F
Water Boils100°C212°F
Body Temperature37°C98.6°F
Room Temperature20-22°C68-72°F
Conversion Formula°C = (°F - 32) × 5/9°F = °C × 9/5 + 32

When to Use Each

Use Celsius for science, international contexts, and if you live outside the US. Use Fahrenheit for everyday weather and cooking in the US.

Frequently Asked Questions

What temperature is the same in both Celsius and Fahrenheit?

-40 degrees is the same in both scales. -40°C = -40°F. This is the only point where they intersect.

Why does the US still use Fahrenheit?

The US adopted Fahrenheit before the metric system became widespread. While there have been attempts to switch, cultural inertia and the cost of conversion have kept Fahrenheit as the primary scale for everyday use.