It's about as heavy as a Chihuahua.
(a.k.a. Chihuahue(o) (FCI standard)
The F&d&ration Cynologique Internationale (FCI) calls for Chihuahuas to weigh about 1.5 to 3 kg. Relative to their body sizes, Chihuahuas have the largest brain size of any dog breed.
It's about four-fifths as heavy as a Brick.
In other words, 2.250 kilograms is 0.780 times the weight of a Brick, and the weight of a Brick is 1.30 times that amount.(Standard, traditional face brick - 1,900 cu. cm (120 cu. in))
A standard, traditional face brick weighs an average of 2.9 kg. The steeple of the Church of St. Martin in Landshut, Germany is said to be the tallest brick tower in the world at a height of 130.6 m (428.5 ft) and was constructed using an estimated 650,000 bricks.
It's about one-and-two-thirds times as heavy as a Human Brain.
In other words, the weight of a Human Brain is 0.5990 times 2.250 kilograms.(adult)
The average weight of an adult human brain is between 1.350 kilograms. In humans and primates, sight and vision utilize about 30 different parts of the brain which together account for about half of the brain's size.
It's about half as heavy as a Gallon of Paint.
It's about half as heavy as a Cat.
In other words, the weight of a Cat is 2 times 2.250 kilograms.(Felis catus) (Domestic; healthy weight)
The average domestic cat should weigh between 4 and 5 kg. Cats are known for their righting reflex, which allows them to land on their feet and survive falls from heights of 1 m (3 ft) up to about 21 m.
It's about two times as heavy as a liter of Water.
In other words, 2.250 kilograms is 2.2499370 times the weight of a liter of Water, and the weight of a liter of Water is 0.44445690 times that amount.(fresh; 4° C / 39.2° F; maximum density)
Contrary to popular belief, 1 liter (0.0.264172052358148 gal) of water at 4° C / 39.2° F (its point of maximum density) weighs 1.000028 kg rather than 1 kg exactly. The total volume of water on the planet Earth is about 13,590,000,000,000,000,000 (13.59 quntillion) L (3,590,000,000,000,000,000 gallons).
It's about one-third as heavy as a Bowling Ball.
In other words, 2.250 kilograms is 0.3306933930 times the weight of a Bowling Ball, and the weight of a Bowling Ball is 3.02394914 times that amount.(most common selection among male bowlers)
With an allowable range of 4.989516070 kilograms, the most-preferred bowling ball weight among adult, male bowlers is 6.803885550 kilograms. Because regulation balls measure the same diameter irrespective of their weight, ball density varies by size and balls weighing less than about 5 kg (11 lbs) will float in water.