What This Calculator Does
This tool converts temperatures between Celsius (°C) and Fahrenheit (°F) in both directions. It is especially handy when adjusting a thermostat that uses one scale while you think in the other, comparing weather forecasts across regions, or following a recipe written for a different country. Choose your direction, type a temperature, and get an instant, accurate answer.
How to Use It
Pick whether you want to convert Celsius → Fahrenheit or Fahrenheit → Celsius, enter the temperature value (decimals and negatives are allowed), and the result appears immediately. For example, a comfortable home thermostat setting of 21°C equals about 70°F.
The Formula Explained
To go from Celsius to Fahrenheit, multiply by 9/5 (which is 1.8) and add 32: $$\text{°C} \times \frac{9}{5} + 32 = \text{°F}$$. The factor \(\frac{9}{5}\) stretches the degree size because a Celsius degree is larger than a Fahrenheit degree, and the +32 shifts the zero point, since water freezes at 0°C but 32°F. To reverse the process, subtract 32 first and then multiply by 5/9: $$\left(\text{°F} - 32\right) \times \frac{5}{9} = \text{°C}$$.
Worked Example
Suppose your oven recipe calls for 200°C. Multiply: $$200 \times \frac{9}{5} = 360.$$ Add 32: $$360 + 32 = \textbf{392°F}.$$ Going the other way, 98.6°F body temperature converts as $$\left(98.6 - 32\right) \times \frac{5}{9} = 66.6 \times \frac{5}{9} = \textbf{37°C}.$$
FAQ
At what temperature are Celsius and Fahrenheit equal? At \(-40°\), where \(-40\text{°C} = -40\text{°F}\).
What is room temperature in Fahrenheit? A typical room temperature of 20–22°C is roughly 68–72°F.
Does this work for negative temperatures? Yes. For example, \(-10\text{°C} = 14\text{°F}\), and the formula handles any value you enter.
