Find Volume and Surface Area of Tube Shape Donut

Minor Radius (r) = m
Major Radius (R) = m
 
Tube Shape Donut Surface Area = m2
Volume = m3
Online calculator helps to calculate the subwoofer vent minimum port diameter or size based on maximum air volume, tuning frequency, number of ports.
Formula:
torus-major-minor-radius
Surface Area = 4π2Rr
Volume = 2π2Rr2
Where,
      R = Major Radius
      r = Minor Radius
Formula:
torus-major-minor-radius
Surface Area = 4π2Rr
Volume = 2π2Rr2
Where,
      R = Major Radius
      r = Minor Radius