It's about one-two-hundred-thousandth as heavy as The Sears Tower
In other words, 999 kilograms is 0.000004950 times the weight of The Sears Tower, and the weight of The Sears Tower is 202,000 times that amount.(officially "Willis Tower" as of 2009) (Chicago, Illinois)
The Willis Tower weighs approximately 201,800,000 kilograms. The outer wall surface of the Tower is covered with black anodized aluminum panels which would total 110,000 sq. m (28 acres) if laid out together.
It's about 250,000 times as heavy as a Die (Dice)
In other words, the weight of a Die (Dice) is 0.00000420 times 999 kilograms.(for six-sided, 16 mm, rounded cube)
A die, of the size most commonly used in board games and casinos, typically weight 0.0041 kilograms. The use of dice and dice-like tools predates written history, with the oldest known examples belonging to a 5,000-year old backgammon set uncovered during an archaeological dig in modern-day Iran.
It's about one-three-hundred-fifty-thousandth as heavy as The Empire State Building
In other words, 999 kilograms is 0.000003020 times the weight of The Empire State Building, and the weight of The Empire State Building is 331,000 times that amount.(New York City, New York)
The Empire State Building weighs approximately 331,000,000 kilograms. About 4% of the building's weight is its 6,000 cu. m (200,000 cu. ft) of limestone façade.
It's about 400,000 times as heavy as a Penny
In other words, the weight of a Penny is 0.00000250 times 999 kilograms.(United States) (formally one-cent coin) (Union shield design, 2010-present)
The weight of a United States penny is 0.0025 kilograms. According to a 2010 report by the United States Mint, the cost of manufacturing and distributing a penny is $0.0179 — more than its face-value.
It's about 550,000 times as heavy as a Playing Card
In other words, the weight of a Playing Card is 0.00000180 times 999 kilograms.(ISO 216 B8 size, 2.5" x 3.5")
A single ISO 216 B8-size playing card weighs 0.0018 kilograms. Although this size is the most common home playing card, many casinos use "bridge size" cards — 2,640 sq. mm (4.036 sq. in) smaller in area.
It's about 700,000 times as heavy as a Paper Clip
In other words, 999 kilograms is 710,000 times the weight of a Paper Clip, and the weight of a Paper Clip is 0.00000140 times that amount.(average)
Notwithstanding the tremendous variation in sizes and materials, a typical paperclip weighs about 0.0014 kilograms. The country of Norway has used the paper clip as something of a national symbol since the end of World War II based on the erroneous notion that the paperclip was invented by a Norwegian, Johan Vaaler. However, the paperclip had already been in existence for at least 30 years by the time of Vaaler patented his paperclip design.
It's about one-eight-hundred-thousandth as heavy as The Golden Gate Bridge
In other words, 999 kilograms is 0.000001240 times the weight of The Golden Gate Bridge, and the weight of The Golden Gate Bridge is 806,000 times that amount.(San Francisco, California and Marin County, California) (Post 1986 weight reduction; total weight of bridge, anchorage, and approaches)
Following the completion of the 1986 project to eliminate excess material, the total weight of the Golden Gate Bridge — including its anchorages and approaches — is 805,000,000 kilograms. The two main cables in the spanning the bridge are spun out of a total of 129,000 km (80,200 mi) of wire.