Temperature Converter

Use this free temperature converter to instantly convert between Fahrenheit, Celsius, and Kelvin. Enter any temperature value and all units update automatically.

How to use this Temperature Converter

Enter a temperature value in any field and the other two units update automatically. Type a temperature in Fahrenheit to instantly see the Celsius and Kelvin equivalents. Type in Celsius or Kelvin and both other scales update at the same time. The converter works for any temperature including negatives — useful for weather, cooking, science, and freezer temperatures.

Frequently asked questions

Q: How do I convert Fahrenheit to Celsius?
A: Subtract 32 from the Fahrenheit temperature, then multiply by 5/9. For example, 98.6°F (normal body temperature) − 32 = 66.6, then 66.6 × 5/9 = 37°C. A quick mental shortcut: subtract 30 and divide by 2 for a close approximation.

Q: What temperature is the same in Fahrenheit and Celsius?
A: The two scales intersect at exactly −40 degrees. At −40, Fahrenheit and Celsius are equal (−40°F = −40°C). Below that point, Celsius values are numerically higher than Fahrenheit, and above it, Fahrenheit values are higher.

Q: What is Kelvin and when is it used?
A: Kelvin is the base unit of temperature in the International System of Units (SI) used in science and engineering. Unlike Fahrenheit and Celsius, Kelvin has no negative values — zero Kelvin (absolute zero) is the coldest theoretically possible temperature, equal to −273.15°C or −459.67°F. Scientists use Kelvin because it makes thermodynamic calculations simpler and avoids negative numbers.

Q: What are some important temperature reference points?
A: Water freezes at 32°F (0°C, 273.15K) and boils at 212°F (100°C, 373.15K) at sea level. Normal human body temperature is 98.6°F (37°C). Room temperature is typically around 68–72°F (20–22°C). A comfortable oven temperature for baking is 350°F (177°C).

Q: Why does the United States still use Fahrenheit?
A: The United States is one of only three countries still using Fahrenheit alongside Myanmar and Liberia. The Fahrenheit scale became deeply embedded in American culture and infrastructure before the metric system was widely adopted internationally. Changing would require updating billions of thermometers, ovens, weather systems, and cultural references.