F.= (C. x 9/5)+32
F.= R.-459.67
F.= 9/5 (K.-273.16)+32
C.= 5/9(F.-32)
C.= K.-273.16
C.= 5/9 (R.-491.67)
R.= F.+459.67
R.= (C.x9/5)+491.67
R.= 9/5(K-273.16)+491.67
K.= C.+273.16
K.= 5/9(F.-32)+273.16
K.= 5/9(R.-491.67)+273.16

F= Fahrenheit
C= Celsius or Centigrade
R= Rankin
K= Kelvin

Rankin is the absolute Fahrenheit scale R.= -459.67F.
Kelvin is the absolute Celsius scale K= .273.16 C.

Celsius vs Centigrade:
Celsius was adopted in place of centigrade, by international agreement in 1948; however, acceptance of the new term has been slow in Europe, and still slower in the United States. Actually, Celsius and centigrade scales differ slightly. The Celsius scale is based on 0 at the triple point of water (.01C.) and centigrade has 0 at the freezing point of water. For all practical purposes the two terms are interchangeable.