1 kilogram is equal to how many grams?

One kilogram is equal to 1000 grams based on the metric system's definition of these units of measure. The metric system operates on a base-10 system, meaning that each kilogram represents 1000 grams. This conversion is fundamental and widely used in various fields, including pharmacy, where precise measurements are critical for medication formulation and dosing.

Understanding this relationship ensures accurate communication and calculations when handling weights in pharmaceuticals. The other options provided suggest incorrect conversions, reflecting potential misunderstandings of the metric system's structure, where larger units like kilograms can be broken down into smaller units like grams by powers of ten.