It's about 2,000 times as big as a Baseball (packed)
In other words, 20.40 bushels is 2,186.96280 times the size of a Baseball (packed), and the size of a Baseball (packed) is 0.00045725515 times that amount.(64% packing density) (MLB rules)
Per Major League Baseball rules, a baseball must measure between about 0.0057247067 bushels and 0.0062151399 bushels. A major league pitcher can throw a fastball at up to 150 kph (91 mph).
It's about one-three-thousandth as big as a Hot Air Balloon
In other words, 20.40 bushels is 0.00033 times the size of a Hot Air Balloon, and the size of a Hot Air Balloon is 3,000 times that amount.(four-person capacity; envelope volume; average)
The average volume of a hot air balloon sufficient to lift four adults is 62,000 bushels. Typically made of nylon or dacron, a balloon envelope of this size typically weighs just 88 kg (190 lbs).
It's about 3,500 times as big as a Baseball
In other words, 20.40 bushels is 3,417.1293120 times the size of a Baseball, and the size of a Baseball is 0.0002926433005 times that amount.(MLB rules)
Per Major League Baseball rules, a baseball must measure between about 0.005724706715 bushels and 0.006215139944 bushels. A major league pitcher can throw a baseball at up to 150 kph (91 mph) in a fastball pitch.
It's about one-three-thousand-five-hundredth as big as an Olympic Swimming Pool
In other words, the size of an Olympic Swimming Pool is 3,400 times 20.40 bushels.(FINA regulation; (minimum capacity)
According to the Fédération Internationale de Natation (FINA), a swimming pool for Olympic and world championship events must measure 50 m by 25 m with a depth of at least 2 m for a total volume of 71,000 bushels. A pool of this size was to be used in Olympic time trials in New Jersey in early 2008, but its component pieces were stolen from a warehouse, likely to be sold for scrap metal.
It's about 4,500 times as big as a Tennis Ball
In other words, 20.40 bushels is 4,564 times the size of a Tennis Ball, and the size of a Tennis Ball is 0.0002191 times that amount.(ITF Standard; for Type 2 ball)
Per International Tennis Federation standard, regulation tennis balls must measure 6.54 cm to 6.86 cm in diameter, for a total volume of 0.004469 bushels. 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.
It's about 6,000 times as big as a Puck (Hockey)
In other words, 20.40 bushels is 6,206.132840 times the size of a Puck (Hockey), and the size of a Puck (Hockey) is 0.0001611309371 times that amount.(Ice hockey)
standard ice hockey puck measures about 0.003287071116 bushels. Hockey pucks can be shot or passed at speeds of up to 160 kph (99 mph) during games.
It's about one-eight-thousandth as big as The Goodyear Blimp
In other words, 20.40 bushels is 0.000125 times the size of The Goodyear Blimp, and the size of The Goodyear Blimp is 8,000 times that amount.(for GZ-20A)
The Goodyear GZ-20 model Blimp measures 163,000 bushels in total volume. A December, 1929 college football game between the University of Florida Gators and the University of Oregon Webfoots (later the University of Oregon Ducks) began with the blimp dropping a parachute-equipped ball from a height of 61 m (200 ft) to the field below.