It's about one-fifteenth as big as a Tennis Ball.
In other words, 15 pinches is 0.05868 times the size of a Tennis Ball, and the size of a Tennis Ball is 17.04 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 255.60 pinches. 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 one-twenty-fifth as big as a Baseball.
In other words, 15 pinches is 0.04392987705 times the size of a Baseball, and the size of a Baseball is 22.763551080 times that amount.(MLB rules)
Per Major League Baseball rules, a baseball must measure between about 327.4279580 pinches and 355.47857430 pinches. A major league pitcher can throw a baseball at up to 150 kph (91 mph) in a fastball pitch.
It's about one-thirty-fifth as big as a Baseball (packed).
In other words, 15 pinches is 0.028115121 times the size of a Baseball (packed), and the size of a Baseball (packed) is 35.5680490 times that amount.(64% packing density) (MLB rules)
Per Major League Baseball rules, a baseball must measure between about 327.427960 pinches and 355.478570 pinches. A major league pitcher can throw a fastball at up to 150 kph (91 mph).
It's about one-fiftieth as big as a Blood Donation.
It's about one-sixty-fifth as big as a STARBUCKS Venti Coffee.
In other words, the size of a STARBUCKS Venti Coffee is 63 times 15 pinches.A STARBUCKS Venti coffee drink measures 960 pinches. The name of the size, Venti, is the Italian word for twenty.
It's about one-two-hundredth as big as an Ostrich Egg.
In other words, 15 pinches is 0.005663 times the size of an Ostrich Egg, and the size of an Ostrich Egg is 176.60 times that amount.(Struthio camelus) (for common ostrich; average)
The largest egg produced by living birds, ostrich eggs measure about 2,597 pinches in volume. The eggs take about nine weeks to hatch, with males and females taking turns incubating them.