Decision guide
100 amp vs 200 amp service
A clear homeowner comparison of service capacity, project triggers and why bigger is not automatically better.
Short answer
200A provides more total capacity than 100A. The decision is not made from service size alone: existing demand, planned equipment, panel configuration, utility scope and load-management options all matter.
Key takeaways
01100A may be adequate for some homes and projects.
02200A may be practical when several high-demand loads are planned.
03A contractor’s applicable load calculation is the decision evidence.
What changes
Increasing from 100A to 200A can require more than a larger panel. Service conductors, meter equipment, the service mast or lateral, grounding/bonding and utility coordination may all enter the scope.
When 100A may remain
A modest project, lower existing demand or suitable approved load management may allow the existing service to remain.
Plan for the home, not one appliance
A ten-year equipment plan gives the contractor better information than designing around only the next EV charger or air conditioner.
Field notes / decision evidence
Compare the decision, not just the number
100A and 200A describe nominal service ratings. Use the same evidence for either path.
If 100A remains
Confirm the calculated demand and the exact equipment plan that the conclusion depends on. If load management is used, identify the approved product and the load it controls.
If 200A is proposed
Ask what physical components must change, who requests utility approval, whether a temporary outage is needed and which work is outside the electrical quote.
If the answer is uncertain
Separate known equipment from assumptions. Utility supply, concealed service routing and future appliance choices can remain provisional until investigated.
Illustrative scenarioExample only: two houses with 100A mains can reach different outcomes because one has electric space and water heat while the other does not. A single amperage label is not a load calculation.
Decision table
What the evidence changes
- 100A
- Potentially adequate depending on actual demand
- 200A
- Greater total capacity; may involve utility-side work
- Decision evidence
- Applicable load calculation and site assessment
Key distinctions
What each rating does and does not establish
Typical project sequence
From question to documented work
- 01Inventory current loads
- 02List near- and long-term projects
- 03Compare retain / manage / upgrade paths
- 04Confirm permit and utility scope
Sequence and responsibilities vary by jurisdiction, utility and scope.
Evidence
Sources and verification
Published by the 200AmpPanel.ca Research Team, a HAUSE specialist property. Updated 2026-09-29.
Questions
Frequently asked
Is 100A enough for an EV charger?
Sometimes. Charger size, existing demand, charging controls and approved energy management all affect the answer.
What should I do next?
Use the Capacity Check to organize what you know, then have a qualified electrical contractor complete the assessment required for the property and jurisdiction.
Your next step
Bring the right facts to the first conversation.
Record the visible service clue, planned equipment and any relevant documents. The free brief organizes your questions; a qualified person verifies capacity and scope.