An electrical takeoff is a count before it is a price: devices, fixtures, panels and circuits from the drawings, then the wire, conduit and boxes between them. The count is where electrical estimates are won and lost, because the labour follows the device count almost linearly and the material follows the run lengths, and both are knowable from the drawing before any rate is applied.
Count the devices, then measure the runs
Receptacles, switches, fixtures, panels, gear and terminations are counted; homeruns and feeders are measured. Electrical takeoff software earns its keep by making both fast and checkable on screen, with each count tied to the sheet it came from so a scope change is re-measured rather than re-guessed.
Labour units are the estimate, not the material
Material moves with the market and labour dominates most electrical bids. Whether you use published labour units or your own history, the takeoff has to produce the quantities those units attach to, which is why a count that cannot be broken down by device type is of limited use.
Carry the takeoff into the job
The quantities are what the material order and the installer's scope refer back to. A takeoff thrown away when the bid is sent means the first question on site, how many fixtures were allowed, has no answer, and the change order that should follow never gets raised.
Questions people ask about electrical takeoff software
Do I need takeoff software for small jobs?
For a service change or a handful of circuits, no: a walk and a list is faster. It starts paying on plan-and-spec work where the count runs into hundreds and a missed panel schedule changes the bid materially.
Should labour units come from a published book or from my own jobs?
Both. A published set is a reasonable starting point and your own completed jobs are the correction. Firms that never compare the two keep bidding at somebody else's productivity.
What is most often under-counted?
Terminations, boxes and the labour in finishing rather than roughing. The devices get counted because they are on the drawing; the work around them is what quietly consumes the hours.