What is a kilogram?
A kilogram is metric unit of weight subdivided into 1,000 grams. The base unit of mass in the International System of Units (SI) is a kilogram and not, as is quite often mistaken, the gram.
One liter of water weighs 1kg.
What are grains?
Grains are a unit of measurement commonly used in the imperial system to measure the weight of small objects such as bullets, arrows, and jewelry.
One grain is equivalent to approximately 0.0648 grams or 0.0023 ounces and are still used in certain industries where precision is crucial, such as in the production of pharmaceuticals and supplements.