Finished floor area. 100 m2 is about 1,076 sq ft.
Usually printed on the main breaker.
0 if gas. Many ranges are 9 to 14 kW.
Baseboards, electric furnace or boiler. Not a heat pump.
Electrical input from the nameplate, not the heating output.
Each fixed load over 1.5 kW: water heater, dryer, hot tub. Example: 4.5, 5.5
0 if none. Common sizes: 32, 40, 48.
0 if none. The cap a Code-approved system holds the charger to.
Estimated calculated demand
100A
Smallest standard service
100A service
Your 100 A service has about 0 A of room on this estimate.
| Load | Counted (W) |
|---|---|
| Basic load (living area) | 6,000 |
| Electric range | 6,000 |
| Other fixed loads over 1500 W | 1,125 |
| Minimum for a dwelling this size | 24,000 |
| Estimated demand | 24,000 |
Planning estimate only. A licensed electrician confirms the calculation for your house under the BC Electrical Code.
Whether a house needs a 60, 100, 125 or 200 amp service depends on the loads it has to carry, not on its age. This tool follows the structure of the dwelling-service calculation in the Canadian Electrical Code (Rule 8-200), which is what a licensed electrician and the inspector use. Enter your living area and the big loads and you get an estimated demand in amps, the smallest standard service that covers it, and how it compares with the service you have now.
It is most useful before you add something large: a heat pump, an EV charger, an electric range, a hot tub or a suite. Our posts on heat pump panel upgrades and whether 60 amp service is enough explain what happens next if the answer is "not quite". If you are still choosing a heat pump, the input figure comes from its size, which this heat pump size calculator helps you estimate.
How the numbers are worked out
The estimate adds these parts, in watts, then divides by 240 volts:
- Basic load: 5,000 W for the first 90 m2 of living area, plus 1,000 W for each additional 90 m2 or portion of it.
- Electric heating: 100% of the first 10 kW plus 75% of the rest.
- Heat pump or air conditioner: counted at its full electrical input. This is conservative, because heating and cooling often do not run together.
- Electric range: 6,000 W, plus 40% of the rating above 12 kW.
- Other fixed loads over 1,500 W (water heater, dryer, hot tub): 25% of each when there is a range; with no range, 100% of the first 6,000 W and 25% of the rest.
- EV charger: counted at its full rated amps, or at the limit set by an EV energy management system if you enter one.
- Minimum: the result is never below 24,000 W for a dwelling of 80 m2 or more (100 A), or 14,400 W under 80 m2 (60 A).
The answer is rounded up to the next standard service size: 60, 100, 125, 150, 200 or 400 amps.
What this tool does not cover
This is a planning estimate, not the Code calculation for your house. It does not cover apartments or multi-unit buildings, a second building such as a garden suite, three-phase supply, farm or commercial loads, or demand factors that apply to unusual equipment. The Code edition in force in BC is the 2024 Canadian Electrical Code (CSA C22.1:24), and its text, and your electrician's reading of it, govern. Changing a service or panel is work for a licensed electrical contractor under a permit.
Frequently asked questions
Is a 100 amp service enough for a house with a heat pump?
Often yes for a modest house with gas or oil heat and a range, but it depends on the other loads. Enter the heat pump input, range and any EV charger and compare the result with 100 A.
What do I enter for a heat pump?
The electrical input from the nameplate (watts or kW), not the heating capacity. Your heat pump installer or electrician can read it for you.
Does this replace an electrician's load calculation?
No. It uses the same structure, but the BC Electrical Code text and the inspector govern. Use it to plan, then have a licensed electrician confirm.
What if the result is close to my service size?
That is where a proper calculation matters. Options include load management, a different appliance choice, or a service upgrade. See our panel upgrade cost guide for how those compare.
Sources
Last verified October 8, 2026. Codes, rebates and permit rules change; confirm with your electrician, Technical Safety BC or your municipality before you rely on a result.