100 Amp vs 200 Amp Service: Which Does Your Home Need?

The amperage of your electrical service sets the ceiling on how much power your home can draw at once. Most older Ontario homes were built around 60 or 100 amp service, which handled lighting, a fridge, and a few outlets just fine. Modern homes ask a lot more. If you are weighing 100 amp against 200 amp service, this guide walks you through how to decide.

What service amperage actually means

Your service amperage is the maximum current your main panel can deliver from the grid. A 100 amp service can run a typical small home with standard appliances. A 200 amp service roughly doubles that headroom, which matters once you start adding high draw equipment or more circuits than the panel has room for.

Upgrading the service is different from swapping a breaker. It changes the main rating of the home, so it involves your local utility and a mandatory safety inspection. If you want to see the full warning list first, read the signs you need an electrical panel upgrade.

When 100 amp service is still enough

You do not always need to jump to 200 amp. A 100 amp service can be a good fit when:

• You own a smaller home or condo with gas heat and a gas range.
• You have no plans for an EV charger, a heat pump, or electric heat.
• Your panel still has open breaker slots and never trips under normal use.
• Your wiring and panel are in good, modern condition.

If your panel is healthy and your power needs are modest, the smarter move may be to leave the service alone and fix only what needs fixing.

When you should upgrade to 200 amp service

Most upgrades happen because the home has simply outgrown its panel. Plan for 200 amp service when you:

• Add a home EV charger, which can draw as much as a small home on its own.
• Install central air, a heat pump, a hot tub, or an electric range.
• Finish a basement, build an addition, or add a secondary suite.
• Run an older 60 or 100 amp panel with no spare slots and frequent trips.

Going to 200 amp also gives you room to grow, so you are not back here in a few years paying to upgrade again.

The EV charger tipping point

A Level 2 charger usually needs a dedicated circuit in the range of 40 to 50 amps. (Verify amperage against the current Ontario Electrical Code and the charger manufacturer at build time.) On a 100 amp service that is already busy, there may not be room, which is why an EV charger and a panel upgrade often happen together.

How to decide for your home

The honest answer depends on a load calculation, not a guess. A licensed electrician adds up your existing demand and your planned additions, then tells you whether your current service can carry it. That assessment is the right starting point, and it is part of how we scope every residential electrical job.

If you are mainly trying to budget, our cost to upgrade to 200 amp service page breaks down the pricing by scenario. We give every customer a clear written quote before any work begins.

Choosing the right electrician

Service upgrades are not a job for a handyman. Hire a licensed Electrical Contractor that pulls the ESA permit, books the utility disconnect, and explains the scope in plain language. Kolji Bros Electrical handles panel and service upgrades across Toronto and the surrounding GTA, with the permit and inspection included on every job.

Frequently asked questions

Is 100 amp service enough for a house in Ontario?

It can be, for a smaller home with gas heat and no major electric loads. Once you add an EV charger, a heat pump, or electric heat, 100 amp service often runs out of room and 200 amp becomes the safer choice.

How do I know if I have 100 amp or 200 amp service?

Check the rating on your main breaker inside the panel. If you are not sure, a licensed electrician can confirm your service size and whether it matches your current needs.

Do I need 200 amp service for an EV charger?

Not always, but often. A Level 2 charger needs a sizable dedicated circuit, and many older 100 amp panels do not have the spare capacity. A load calculation tells you for certain.

Can I add 200 amp service without rewiring the whole house?

Usually yes. A service upgrade replaces the panel and service equipment, not the branch wiring. If your home also has old wiring, your electrician may recommend addressing that separately.

Does a service upgrade need a permit in Ontario?

Yes. Any service upgrade needs an ESA permit and a final inspection. A licensed contractor handles the permit and meets the inspector on site.

Not sure which service size your home needs? Kolji Bros Electrical runs the load calculation, gives you a clear written quote, and handles the permit and inspection from start to finish. Serving Toronto and the surrounding GTA.

Get your free quote