It's about three-fifths as heavy as a Football (Soccer)
In other words, 250 grams is 0.580 times the weight of a Football (Soccer), and the weight of a Football (Soccer) is 1.70 times that amount.(a.k.a. Soccer, a.k.a. Association Football) (FIFA Law 2 specification)
According to FIFA's Law of the Game number 2, a football must weigh between 410 g and 450 g. An artifact on display at the Smith Art Gallery in Museum in Stirling, Scotland is said to be the world's oldest football and is about one-third to one-half the size of a modern football.
It's about one-and-nine-tenths times as heavy as a Battery (D)
In other words, 250 grams is 1.850 times the weight of a Battery (D), and the weight of a Battery (D) is 0.5410 times that amount.(Alkaline)
A "D" size battery weighs 135 g. The D size battery is the oldest of the modern battery sizes, first invented by the National Carbon Company in 1898.
It's about two-fifths as heavy as a Basketball
In other words, 250 grams is 0.40084047670 times the weight of a Basketball, and the weight of a Basketball is 2.4947580350 times that amount.(NBA official ball standards, Size 7)
A regulation NBA basketball, manufactured by Spalding, is known as a Size 7 ball and weighs 623.68950875 g. These balls have 4,118 pebbles each with a diameter of 2.5 mm
It's about two-and-a-half times as heavy as a Deck of Cards
In other words, the weight of a Deck of Cards is 0.370 times 250 grams.(ISO 216 B8 size, a.k.a. "poker size" 63 x 88 mm, 52-card deck)
A deck of 52 ISO 216 B8-size playing cards weighs 94 g. Utilizing nearly 3,700 decks, the record-holding largest card tower was built in early 2010, stood over 3.5 m (11 ft), and weighed over 230,000 grams.
It's about four times as heavy as a Battery (C)
In other words, 250 grams is 3.80 times the weight of a Battery (C), and the weight of a Battery (C) is 0.260 times that amount.(Alkaline)
A "C" size battery weighs 65 g. C batteries are typically used in medium-drain devices such as musical instruments.
It's about one-fourth as heavy as a liter of Water
In other words, 250 grams is 0.2499930 times the weight of a liter of Water, and the weight of a liter of Water is 4.000112 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 1,000.028 grams 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 four-and-a-half times as heavy as a Tennis Ball
In other words, 250 grams is 4.330 times the weight of a Tennis Ball, and the weight of a Tennis Ball is 0.2310 times that amount.(ITF Standard; for Type 2 ball)
Per International Tennis Federation standard, regulation tennis balls must weigh about 56.0 g to 59.4 g. Competition balls are also tested for bounce height, with the standards requiring that a ball dropped from 254 cm must bounce back to a height of 135 cm to 147 cm.