Commercial Branch Estimating


New User
Ann Arbor

I have been working for an electrical contractor for about 3 years now and for the past 6 months I have been given small electrical projects to do take-offs and estimates on. I was given no training on this, other than resources online, the NEC, and using what I learned from my college education (Construction Management) to come up with a somewhat complete electrical estimate.

My biggest issue seems to be understanding how to take-off branch electrical. I generally create a simple assembly for receptacles and switches. For example, for each receptacle I count, it would have a device box, switch, cover-plate, 10' or so of MC or EMT, and a ceiling box. From that ceiling box, I would move to the next one and so forth.

My biggest hang-up is when combining circuits (generally do 4 circuits per home-run). My supervisor just told me to take my EMT count and multiply it by 3.6 for lighting and 4.6 for receptacles. So if I have 150' of EMT for lighting circuits 1, 3, 5, and 7, I would multiply 150*3.6 giving me 540' of wire. This just seems wrong to me. Should I be multiplying each circuit by 3.6? giving me 150*4*3.6=2160'?

Like I said, I have little to no knowledge of electrical estimating, especially commercial. I am pretty much going off of what I could find online and advice from people in my office. Smaller projects it doesn't seem to matter much, but some of the larger projects I am doing ($800,000 to $1,000,000 for electrical) can become a nightmare.


Senior Member
A lot depends on if the project specs allow your circuits to share a neutral. But even if they do, the 3.6 and 4.6 numbers seem kind of low.

With 4 circuits in a conduit, and with neutral and ground seems like you should multiply the conduit length by 6.

I think there is also a rule that you have to double the price if its a change order and not a competitive bid. :)