Laying out a balanced panel
A breaker panel works best when the load is split evenly between its two legs, so neither bus runs hot while the other sits idle. Building that schedule by hand — numbering circuits, tracking poles, and tallying each leg — is tedious and error-prone. This calculator builds the schedule, assigns circuits to balance the legs, and checks the total against the main breaker.
How it works
Each circuit’s load is converted to volt-amperes. Amps are multiplied by the circuit voltage — 120 V for single-pole, 240 V for two-pole — while VA is used as entered. Single-pole circuits are placed on whichever leg currently carries less load, a greedy balance that keeps legs A and B close. A two-pole 240 V circuit draws from both legs equally, so half its VA lands on each.
Each leg’s current is its VA divided by 120 V (line-to-neutral), and the higher of the two legs is the value that must stay under the main breaker rating. The tool also totals the connected load and shows it as amps at 240 V for a quick service-size sense check.
Example and notes
A 100 A panel with kitchen, lighting, a 40 A range, and a 4500 VA water heater balances the single-pole circuits across legs while the two-pole loads split evenly, and the highest leg stays well under 100 A. Remember this is connected load: apply NEC Article 220 demand factors before sizing the service, and size the main and feeder to the resulting demand load rather than the raw connected total. Local amendments to the NEC may also apply.