Formula :-
To Convert Celsius to Fahrenheit 

°C  x  9/5 + 32 = °F  OR °F = (1.8 x °C) + 32

To Convert Fahrenheit to Celsius
 
(°F  -  32)  x  5/9 = °C OR °C = (°F - 32) / 1.8


Trick To Convert Celsius to Fahrenheit :


You will not get the accurate value of Fahrenheit using this trick.

Step 1 :  Double the celsius

Step 2 : Add 30

For example 

lets take 15 °C

Step 1 :  Double the celsius 15 x 2 = 30

Step 2 : Add 30 so 30 + 30 = 60°F

So it is quite near to the actual answer 59°F

Now to convert  Fahrenheit to Celsius 

Step 1 : Subtract  30

Step 2 : Divide by 2