Estimate electrical panel capacity, used capacity, remaining amps, remaining watts, added load impact, panel load percentage, and recommended panel size for planning panel upgrades or new circuits.
Panel capacity:
The calculator estimates total panel capacity in amps and watts from panel size, voltage, and phase type.
Existing load:
Existing demand load can be entered as amps, watts, or kilowatts.
Added load:
The planned added load is adjusted by the selected demand factor, then added to the existing load to estimate remaining capacity.
An electrical panel capacity calculator helps estimate whether a panel has enough room for a new load.
It can help with EV charger planning, HVAC upgrades, appliance additions, subpanel planning, workshop circuits, garage circuits, shed panels, and service upgrade planning.
Your result shows existing load, added demand load, total load after addition, used capacity percentage, remaining amps, remaining watts, capacity target, recommended panel size, and comparison scenarios.
Compare your calculated demand load to the panel rating. If the total demand load is close to or above the panel size, the panel may need further review or an upgrade.
No. A panel may have open breaker spaces but still be limited by service size, feeder size, bus rating, or calculated load.
Many planning estimates prefer staying below 80% for comfort, but official requirements depend on the load calculation, equipment, and local electrical code.
No. This is a simplified planning tool. Final panel capacity depends on electrical code, dwelling calculation rules, nameplate ratings, service conductors, panel ratings, utility requirements, and local inspection rules.