Ask three electricians what a panel upgrade costs and you may hear three very different numbers. That's not because anyone is guessing. It's because "panel upgrade" covers several different jobs, and the price follows the scope. Here is what actually moves the number on a California home.
1. Panel swap or full service upgrade?
Replacing a worn 100-amp panel with a new 100-amp panel is the simplest version. A true electrical panel upgrade from 100 amps to 200 amps usually means a new meter base, larger service conductors, new grounding and coordination with the utility. More material, more labor, more approvals.
2. Overhead or underground service
Overhead services are generally easier to upgrade: the mast and weatherhead are replaced and the utility reconnects the drop. Underground services may need larger conduit, and if the existing conduit can't be reused, trenching becomes part of the project.
3. Where the panel sits
Current rules require working clearance around the panel and restrict certain locations. If the old panel is in a closet or behind a gas meter, it may have to move, and every circuit must be extended to the new spot.
4. What the utility and building department require
Every California panel upgrade needs a permit and inspection, and the utility has its own standards for meter height and location. Lead times vary a great deal between utilities and seasons.
5. What you find when the cover comes off
Double-tapped breakers, aluminum branch wiring, missing grounds and scorched bus bars all need correcting. An electrical inspection beforehand keeps surprises out of the quote.
Do you need the upgrade at all?
Sometimes not. If the service has spare capacity but the panel is physically full, a subpanel is cheaper. If you're adding one EV charger, a load-management device may let the existing service carry it. And if you're adding solar or a battery, the right panel choice can avoid a second upgrade later. A load calculation answers the question with numbers.
Getting a quote you can compare
Ask each electrician to itemize the panel, the service equipment, the permit, utility coordination, grounding and any wall repair. Quotes that list the same scope are the only ones worth comparing.