Both are listed in the dictionaries, but 99% of all people say shilo and most people will probably not even have heard the k-pronunciation. The k-sound is still common in Finland afaik, I also knew a very old lady from Stockholm with that pronunciation.
Can I clarify if this is the full word for kilogram or if it literally translates to "kilo"? Tack!
East of the US essentially everyone uses kilos to describe weight. That's because it's short for a unit called the kilogramme-weight that's defined as the weight of a one kilogramme mass object (1 kg → 1 kg wt), not the kilogramme itself.
Because gravitational force is (essentially, or close enough for everyday purposes) the same across the planet a mass unit can be used to measure weight. And yes, outside of the US we use metric measurements including the kilogram.
That's correct. However, in everyday language mass and weight are interchangable. A "kilo" has no scientifical meaning (a thousand, but a thousand of what? Kilogramme, kilometre, kilosecond, kilotesla, kilojoule... it has to be specified), however nobody uses the correct "kilogramme" while talking about the mass of a person or while shopping in a supermarket.