If you've been told you need a 200 amp panel, it's fair to ask whether that's true or whether it's the default answer. Here's how to think about it honestly.
What the number means
Amperage is how much electricity your home can draw at once, not how much it uses over time. A 100 amp service was standard for decades and still runs plenty of homes fine. The question isn't the age of the number — it's whether your peak demand fits inside it.
The mistake almost everyone makes
Homeowners look at the panel, see empty breaker slots, and conclude there's room. Empty slots are physical space, not capacity. You can have six free slots on a service that's already at its limit, and adding a load to it is how you end up with nuisance tripping at best and an overheated bus at worst.
The real answer comes from a load calculation: the sum of what's connected, weighted by how it's actually used, against what the service can carry. It takes an electrician a few minutes and it's the only method that means anything.
When 100 amps is genuinely still fine
Gas heat, gas water heater, gas range, no air conditioning, no EV. That home is not straining a 100 amp service, and upgrading it buys you nothing today. We'll say so.
When 200 amps becomes necessary
The tipping point is usually electrification. Central air conditioning, an EV charger, a heat pump for heating or hot water, an induction range, a pool heater — each of these is a substantial continuous load, and stacking two or three of them on a 100 amp service is where it stops working. Adding solar with a battery frequently pushes it over as well.
The other trigger is age. If the panel is original to a 1950s or 60s home, the question isn't only capacity — it's whether the equipment itself is still safe. Some mid-century panels should be replaced regardless of load.
What about 400 amps?
Uncommon in ordinary homes, but increasingly real for larger properties running two EVs, a heat pump, a pool, and a detached unit. It's a bigger job than a 200 amp upgrade and worth knowing about before you plan the rest.
The practical advice
If you're planning anything electric in the next few years — a car, a heat pump, a remodel — get the load calculation done now. Upgrading once, ahead of the work, is far cheaper than discovering the ceiling three separate times.