If you take it a step further and try to convert a mass in kilos to ounces, then things are likely to get even trickier.
And what about scientific conversions, where you really need to be precise?
http://www.WeightConversion.Org provides an easy way to convert mass in kilos to pounds, or to any other unit of mass instantly.
This can be quite handy if you are trying to see/find out how a person's weight in kilograms would translate into his/her weight in pounds.