Kilogram is the correct spelling of 1, 000 grams. A kilogram is a measure of weight in the metric system.
Kilogramme is an old British spelling variant of “kilogram”. “Kilogramme” is a French spelling of the word and as French-influenced English(especially in England) for hundreds of years. T
he spelling “kilogramme” continues in use until today.
It is better to use “kilogram” as it is more common in English.
Kg is the shortened form of “kilogram” and is often used in English even in spoken English.