Conventional wisdom says “you need 200A service to add a Level 2 charger”. That’s wrong for most homes. Here’s the actual decision tree.
Step 1: Find your panel amperage
Look at the main breaker at the top of your panel. The number on the handle is your service amperage — 60, 100, 125, or 200A in most homes.
Step 2: Run the panel calculator
This is the only step that actually matters. Our free panel calculator walks through OESC Rule 8-200 — the same load math your electrician runs — and tells you exactly how much headroom your existing service has.
Step 3: Interpret the result
You’ll get a calculated load in amps. Compare to your service:
- Under 80% of your service amperage — you have plenty of room. Add a 40A or 48A charger directly. No panel upgrade needed.
- 80–100% of your service amperage — tight, but a 32A charger usually fits. Load management can also help.
- Over 100% of your service amperage — you’re overloaded even before the charger. Two options: panel upgrade ($3,500–$8,000) or load management device ($1,500–$2,500).
The load management alternative
A device like the DCC-9 or Wallbox Power Boost watches your panel load in real time and throttles the charger down when other big loads (range, dryer, AC) are running. It lets you add Level 2 to a 100A panel that’s technically “full” on paper. About $1,500–$2,500 installed vs $4,000–$8,000 for a panel upgrade.
See our load management page for the full story.
When you actually do need a panel upgrade
- 60A or 100A service in a home that’s already maxed out (electric range + dryer + AC + hot tub + tankless water heater).
- You’re planning to add more than just an EV charger (heat pump, induction range, second charger).
- The existing panel is Federal Pacific / Stab-Lok — it needs replacing anyway.
- You want long-term future-proofing for two EVs and a heat pump.
What does it cost to find out?
Nothing — the panel calculator is free and the answer is yours in two minutes. Save the result to your account and we’ll quote against it directly.