conversion factors

could some-one give me the conversion factors for kelvin, rankine, fahrenheit, and celsius please, im wring a vb proggie and the numbers i have are not correct:

here are the incorrect conversion factors:
origin = Text1.Text
r = origin
f = r - 459.67
c = (f - 32) / (9 / 5)
k = c + 273.15

somewhere in there it is screwing up, id like to use fractions over decimals

thanks

kelvins = degrees Celsius + 273.15
degrees Celsius = kelvins - 273.15
degrees F = degrees C x 1.8 + 32.
degrees C = (degrees F - 32.) / 1.8
To convert from Fahrenheit to Rankine, add 459.67.
To convert from Rankine to Fahrenheit, subtract 459.67.
To convert from kelvin to Rankine, multiply by 1.8.
To convert from Rankine to kelvin, divide by 1.8

ok, thanks, its working fine now:
http://ccb056.zapto.org/files/convert.zip