100 amp vs 200 amp service: what do I need in Massachusetts?
Answer
A 100A service can still work for some homes, but many modern load profiles are better served by 200A. The right decision depends on actual load calculations, not guesswork.
If your home is adding EV charging, electric HVAC, induction cooking, or major renovation scope, 200A is often the safer long-term path.
How to choose the right service size
Service size should be based on present and planned demand.
- 100A may be enough for smaller homes with modest electric loads.
- 200A is often preferred for larger homes or electrification upgrades.
- Frequent tripping and panel crowding are signs that capacity planning is overdue.
Massachusetts context
In Massachusetts, service upgrades generally require licensed work, permits, and inspection. Utility coordination may be required depending on meter and service equipment scope.
When upgrading from 100A to 200A makes sense
Schedule a service-size review before purchasing major electric equipment.
- You are planning EV charging, heat pumps, or electric water heating.
- Your panel has no practical space for additional required circuits.
- You want to avoid staggered upgrades that cost more over time.
Review Panels & Service for capacity planning and upgrade options.