The scale for measuring temperature used internationally where the freezing point of water is zero and the boiling point of water at sea level is 100 degrees. To convert from centigrade into Fahrenheit, multiply the centigrade temperature by 1.8 then add 32 to the product (C*1.8+32=F). To convert from Fahrenheit to centigrade, subtract 32 and then divide by 1.8 ((F-32)/1.8).