Home Electrical Load Calculator

A residential load calculation estimates the total electrical demand of your home — all appliances, lighting, HVAC, and any new loads you want to add. Under NEC Article 220, a licensed electrician must verify that your panel's rated amperage is sufficient to handle that total demand before adding circuits. This calculator uses the Standard Method (NEC 220.14) which is accepted by LADBS for residential permit applications throughout the City of Los Angeles.

Available headroom is the difference between your panel's rated capacity and your estimated current load. Per NEC 210.20, continuous loads should not exceed 80% of panel capacity. If the calculator shows at least 40–50A of usable headroom, a Level 2 EV charger can likely be added without panel work. Less than that, and Jorge will recommend a load management device, a sub-panel, or a full 200A panel upgrade depending on your situation.

NEC Article 220 defines how electricians calculate the total electrical load for a residential property. It includes general lighting loads (3 VA per square foot), small appliance circuits (1500 VA per circuit, minimum 2 circuits), laundry circuits, and all fixed appliances. For loads over 3,000 VA, NEC allows a 35% demand factor on the remainder — which reduces the calculated load to reflect real-world usage patterns. This is the same approach used by LADBS-permitted electrical contractors in Los Angeles County.

A 100A panel delivers roughly 80 usable amps of continuous capacity (at the 80% NEC rule). Once you subtract typical residential loads — HVAC, water heater, kitchen appliances, lighting — the remaining headroom may be as little as 10–20A. A Level 2 EV charger needs 40–60A of dedicated circuit capacity. In most cases, 100A homes require a panel upgrade to 200A before a Level 2 charger can be added safely and legally. A 200A panel gives roughly 160 usable amps — plenty of room for an EV charger plus all other home loads.

A load management device (such as a Span panel, Emporia Vue, or a dedicated EV energy management controller) monitors your home's real-time electrical usage and automatically reduces charger output when other large loads — like your AC or oven — are running. This allows some 100A homes to add an EV charger without a full panel upgrade. Jorge evaluates whether this option is viable for your specific home during the free estimate.

Installing an EV charger without a permit from LADBS is a code violation throughout the City of Los Angeles. Consequences include: potential voiding of homeowner's insurance; a required disclosure obligation when selling your home; potential fines and a LADBS correction notice; and rejection of your federal 30C tax credit filing. LED Guys pulls all permits before work begins — every time, no exceptions.

The address lookup queries public property records to retrieve your home's square footage, year built, and other details. This saves you from having to find this information manually and reduces input errors. The data is pulled using publicly available assessor records for California properties. The tool uses this to pre-fill the square footage field, which determines your NEC general lighting load. Jorge will verify all measurements during the free on-site estimate.