The same National Electrical Code math an electrician runs, in about two minutes. Enter the house, the heat and air, and every appliance and motor, including the ones most people forget: sump pumps, exhaust fans, the disposal. See the biggest Level 2 charger your panel can carry and whether a panel upgrade is really needed.
NEC 220.83(A), the optional method for adding a load to an existing dwelling. The strict line counts the charger at 125 percent and never less than 7,200 VA, the way some inspectors require. A free site visit confirms the real panel, the real nameplates and the run before any price is firm.
Section 220.83 of the National Electrical Code is the optional method for adding a load to an existing house, which is exactly what an EV charger is. It adds 3 volt amps for every square foot of living space for lighting and outlets, measured to the outside walls and leaving out the garage and unfinished space, 1,500 volt amps each for the two kitchen small appliance circuits and the laundry circuit, and the nameplate rating of every appliance and motor that is fastened in place. The first 8,000 volt amps count at 100 percent and everything above that at 40 percent, because not everything runs at once.
Heating and cooling are added on top at the larger of the two, because the furnace and the air conditioner never run flat out at the same time. Electric heat is counted at 65 percent, or 40 percent when it is baseboard heat in four or more separately controlled rooms. A heat pump counts at full compressor rating plus 65 percent of its backup heat strips. Divide the total by 240 volts and you have the amps your house can draw on a worst case evening.
Read as written, 220.83(A) puts a hardwired EV charger in the same pool as the range and the dryer, at its nameplate rating, so it shares the 40 percent factor. The calculator tries a 48, 40, 32 and 24 amp charger in turn and picks the biggest one where the house plus the charger still fits under the main breaker. Because an EV charger runs for hours at a time, some inspectors instead add it on top at 125 percent of its output, and never less than the 7,200 volt amp floor in section 220.57. That reading leaves less room, and it is shown as the strict line in your result. Which one applies is your town inspector's call, and the site visit settles it.
Most online calculators skip the sump pump, the ejector pump, the bathroom fans, the disposal and the dishwasher. Each one is small, but together they are often 3,000 to 5,000 volt amps, and in a basement heavy suburb like ours nearly every house has a sump pump. Leaving them out is how a homeowner ends up with a 48 amp charger on a panel that trips every time the dryer and the oven run.
It trusts what you type. It does not know whether your panel has open breaker spaces, whether the bus is rated for the main, whether the service entrance cable matches the breaker, or whether the previous owner added a hot tub on a doubled up breaker. That is what the free site visit is for. Every estimate we send is confirmed in person before it becomes a firm price, and the municipal inspector checks the finished circuit.
We use the optional method for dwellings in Article 220 of the National Electrical Code. General lighting at 3 volt amps per square foot, two small appliance circuits and a laundry circuit at 1,500 each, every fastened in place appliance at nameplate, the first 8,000 volt amps at 100 percent and the rest at 40 percent, then the larger of air conditioning or electric heat. That is section 220.83(A), the method the code gives for adding a load to an existing house, and a hardwired charger counts as one of those fastened in place appliances. The total has to fit under the main breaker. Some inspectors count the charger more strictly, at 125 percent of its output on top of everything else, so the calculator shows that answer too.
Often, yes. A gas heat, gas range, gas dryer home on 100 amps usually has room for a 32 to 48 amp charger. An all electric home on 100 amps usually does not without a load managing charger or a service upgrade. Run the numbers above and see.
Because the code counts every fastened in place appliance, not just the big ones. A sump pump, an ejector pump, bathroom exhaust fans, a disposal, a dishwasher and a microwave add up to a few thousand volt amps. Leaving them out makes a panel look like it has more room than it does.
It is the same method and the same math, but it depends on what you type in. An electrician reads the actual nameplates, counts the real circuits and checks the panel in person. We confirm every estimate with a free site visit before anything is booked, and the permit inspector checks the finished work.
You have three options before a panel upgrade: a load managing charger that throttles itself when the house is busy, a smaller 24 or 32 amp charger that still fills most cars overnight, or a circuit sharing device on the dryer or range circuit. A full 200 amp upgrade is the last resort and we tell you honestly when it is the right one.
A dedicated 50 or 60 amp circuit, your charger hardwired or on a NEMA 14-50 outlet, permit and inspection included. Most homes $1,200 to $2,500.
Learn more →Gen 3 and Universal Wall Connector installs on a 60 amp circuit for full 48 amp charging. Works with Tesla, Ford, Rivian, Hyundai and any NACS car.
Learn more →Hardwired up to 50 amps or plug-in on a NEMA 14-50, with the amperage set to what your panel can actually carry. Permit and inspection included.
Learn more →100 amp or full panel? We run the load calculation first and only upgrade to 200 amp when it is the honest answer. Often a load-managing charger avoids it.
Learn more →Level 2 stations for apartments, condos, offices, shops and fleets. Load studies, networked chargers, ComEd business rebates and Illinois grant paperwork.
Learn more →Charger tripping the breaker, charging slow, error lights, or a bad install from someone else. We diagnose it, fix it, and bring it up to code.
Learn more →Up to $2,500 for income qualified households, up to $750 for everyone else. 2026 funds are spent, the next window opens January 1, 2027. We check eligibility and file it.
Learn more →Reach out, get a same day estimate, confirm it with a free visit, book a day.
