Free tool · Electrical Readiness Checker
Three facts about your house decide whether home charging is a simple install or a project: your panel’s size, the spare room in it, and where the car sleeps. This page walks you through reading all three — no electrician required for this part — and turns them into a straight verdict.
Step 1 — Read your main breaker
Open your electrical panel door. The main breaker — usually at the top, larger than the rest — is stamped with a number: 100, 150, or 200 are the common ones. That number is your home’s total electrical service in amps, and it’s the ceiling everything else shares.
Step 2 — Count the spare slots
A 240V charging circuit needs a double-pole breaker, which takes two adjacent slots. Count the blank plates or unused breakers in your panel. Two or more spare slots is room to work with; a panel with every slot filled isn’t a dead end — it means load management or a subpanel enters the conversation.
Step 3 — Measure the run
Where does the car sleep relative to the panel? A charger on the wall next to the panel is the cheapest install there is. Every ten feet of wire run, wall penetration, or finished-ceiling crossing after that adds cost — the Install Cost Guide prices each one.
Your verdict
| Panel | Spare slots | Circuit you can run | Verdict |
|---|---|---|---|
| 200A | 2+ | 60A · 11.5 kW | Ready — full-speed Level 2 |
| 200A | 0–1 | 40–50A with a breaker shuffle | Ready, minor panel work |
| 100–150A | 2+ | 40A · 9.6 kW | Ready for most drivers |
| 100A | 0–1 | Load-managed 40A | Ready with load management |
| Under 100A | Any | — | Talk to an electrician first |
Why 40A is enough for most homes: a 40A circuit adds roughly 290 miles of range over an 8-hour night. Unless you regularly arrive home near empty and leave at dawn, the bigger circuit buys speed you’ll never use. The math lives in Charging Speed & Cost.
Next steps: the Electrical Setup hub explains the install itself, and the Buying Guides match chargers to the circuit your verdict gives you.