Temp Converter with Kelvin

[Vexis]

I'm not exactly understanding your conversion methods, but this is how I would do it:

print("K for kelvin, C for Celsius, F for Fahrenheit ")

option = None
while not option in ['c', 'f', 'k']:
    option = input("Enter Selection: ").lower()


temp = float(input("Input Temperature in {}: ".format(option.upper())))
conversions = dict(kelvin=None, celsius=None, fahrenheit=None)

if option == 'k':
    conversions.update([('celsius', temp-273.16), ('fahrenheit', (temp+273.16)*(9/5)+32), ('kelvin', temp)])
elif option == 'c':
    conversions.update([('celsius', temp), ('fahrenheit', temp*(9/5)+32), ('kelvin', temp+273.16)])
elif option == 'f':
    conversions.update([('celsius', (temp-32)*(5/9)), ('fahrenheit', temp), ('kelvin', (temp-32)*(5/9)+273.16)])

print(conversions)