Shell Size to Height & Diameter (#10)

Their size, based on a distinctive unit, categorizes the shells of aerial fireworks. The number indicates the inner diameter of the fireworks launcher. Big fireworks shells are also measured with the Japanese unit called shaku (=30.3cm), and #10 shells are called shaku-dama in some cases.
#10 shell = shaku-dama’s outer diameter is approximately 28.5cm
Fireworks with bigger shells rise higher and form a larger sphere in the air.
The height at which #10 shell (shaku-dama) scatters: approximately 300m
The diameter of which sphere the fireworks shell forms: approx. 280m (approximately 140m radius)