Can a 125 Amp Panel Handle a Heat Pump and an EV Charger?
Usually yes — it gets tight if your cooking, drying and water heating are electric. With a heat pump and an EV charger on 125 A service, an example 1,800 ft² home reaches about 85 A (green) with gas appliances and 120 A (yellow) with an electric range, dryer and water heater (NEC® 220.83).
That leaves about 40 A free in the gas home and 4 A in the electric one. If it’s tight, “set the ev charger to 32 a” brings the busier home to about 117 A.
Two example homes
Gas appliances
1,800 ft², gas cooking, drying and water heating, adding a 3-ton heat pump and 40 A charger
Green · 85 A of 125 AElectric appliances
1,800 ft², electric range, dryer and water heater, adding a 3-ton heat pump and 40 A charger
Yellow · 120 A of 125 AWorked example · NEC® 2023 220.83(B)
1,800 ft², electric range, dryer and water heater, 125 A service, adding a 3-ton heat pump and 40 A charger
| General lighting and receptacles: 1,800 ft² × 3 VA | 5,400 VA |
| Kitchen small-appliance circuits: 2 × 1,500 VA | 3,000 VA |
| Laundry circuits: 1 × 1,500 VA | 1,500 VA |
| Dishwasher | 1,200 VA |
| New heat pump, 3 ton (heating/cooling) | 7,200 VA |
| Electric range | 12,000 VA |
| Electric dryer | 5,000 VA |
| Electric water heater | 4,500 VA |
| New EV charger, 40 A | 9,600 VA |
| First 8,000 VA at 100% | 8,000 VA |
| Remainder 34,200 VA at 40% | 13,680 VA |
| Heating and cooling at 100% | 7,200 VA |
| Demand ÷ 240 V | 120.3 A of 125 A |
Yellow — fits, but tight · 5 A free
If it doesn’t fit
Set the EV charger to 32 A
Most hardwired chargers can be limited by the installer. At 32 A you still add about 25 miles of range per hour.
After: 117.1 A · yellow
Add an energy management system
A listed load manager pauses or slows the new charger when the house is busy, so it no longer adds to the peak.
After: 104.3 A · yellow
Check whether a 2.5-ton heat pump is enough
Many systems are oversized. A Manual J load calculation tells you the size your home actually needs.
After: 115.3 A · yellow
Upgrade the panel or service
A main panel replacement in a single-family home had a median cost of about $3,500 in a 2025 national survey. If the service itself must grow, utility-side costs add a similar median amount, and rewiring can push totals to $30,000 or more.
Free download
Panel Capacity Worksheet
A printable sheet to map your panel, list your big appliances and ask an electrician the 10 questions that matter before a quote.
Questions
Does a heat pump replace my air conditioner in the calculation?
Yes, in our tool a new heat pump takes over from an existing central AC or heat pump, since one system does both jobs. Electric backup heat strips still count separately.
What size breaker does a heat pump need?
Whatever the outdoor unit’s nameplate says: the MCA sets the wire size and the MOCP is the largest breaker allowed. Tonnage alone isn’t enough to know.
How is an EV charger counted in the load calculation?
Under NEC® 2023 220.57 at 7,200 VA or the charger’s nameplate, whichever is higher. A 40 A charger counts as 9,600 VA.
Can a load management device avoid a panel upgrade?
Often. A listed energy management system pauses or slows the charger when the house is busy, and NEC® 2023 lets the calculation use its setpoint instead of the full load.