wikiHow Celsius to Fahrenheit Calculator Here's how to convert Celsius to Fahrenheit manually using a calculator: Multiply the temperature in Celsius by 1.8 (which is the same as multiplying by 9/5). Add 32 to the result from step 1. The final result is the temperature in Fahrenheit. For example, let's say you want to convert 25 degrees Celsius to Fahrenheit: Multiply 25 by 1.8: 25 × 1.8 = 45. Add 32 to 45: 45 + 32 = 77. The temperature of 25°C is equivalent to 77°F. So, 25°C is equal to 77°F. Here's another example: let's say you want to convert 0 degrees Celsius to Fahrenheit: Multiply 0 by 1.8: 0 × 1.8 = 0. Add 32 to 0: 0 + 32 = 32. The temperature of 0°C is equivalent to 32°F. So, 0°C is equal to 32°F. Page