How to calculate Junction Box suggested by Smart Junction Box manufacturer?

  How to calculate today's investigation of the switch box, junction box, many view the Internet, are summarized by Smart Junction Box manufacturer as follows:

1 For concealed: the number of switch box with the same number of switches, junction box number + number = number of sockets + lights crossing the middle of the number of boxes for the next installation: the number of switch box with the same number of switches, the number of outlet box with the same number of outlets.

2.at least: How many lighting fixtures, fans, and so there are at least the number of electrical equipment junction box, and then coupled with the middle of crossing the box; the number of switches, sockets and there are that many switch boxes; a budget should also consider: Concealed pipeline due to the embedded position and burial depth and other factors, sometimes need to shift or need additional boxes, and then consider the 10 to 20% margin.

3 junction box, switch box, the average volume of pipeline meter 2 m.