Panel Size Calculator
Enter the home's floor area and the power of the main appliances in kW. The calculator applies a simplified version of the US optional load method at 240 V and suggests the panel size, with room to grow.
- Panel amps
- Demand load
- Spare capacity
Use nameplate kW. Leave an appliance at zero if it runs on gas.
Most of a home's load is counted at a reduced rate. The first 10 kVA counts in full and the rest at 40%, then air conditioning is added in full. A 2,000 sq ft home with an electric range, dryer, water heater and 3.5 kW AC needs about 93 A, so a 100 A panel. Adding a 7.2 kW EV charger pushes it to 125 A.
Panel size chart
Range, dryer, water heater and 3.5 kW AC. Search for a home size.
| Home (sq ft) | Load (A) | Panel (A) | With EV (A) |
|---|---|---|---|
| 1000 | 88 | 100 | 100 |
| 1500 | 90 | 100 | 125 |
| 2000 | 93 | 100 | 125 |
| 2500 | 95 | 100 | 125 |
| 3000 | 98 | 100 | 125 |
| 4000 | 103 | 125 | 125 |
| 5000 | 108 | 125 | 125 |
Simplified US method.
Home size and panel
With range, dryer, water heater and AC. Slide the floor area.
The panel fills with breakers as the load grows.
How to size a panel
Loads to amps. Step through it.
General
3 VA per sq ft.
Heat pumps, EV chargers and induction ranges are the loads that most often need a bigger panel.
100, 200 or 400 amp
Panel sizes. Compare them.
Small homes.
Most homes.
Large homes.
Many older homes have 100 A. Most new homes get 200 A.
Before you upgrade
Panel checks. Tick each item.
Tick each item as you go.
A panel upgrade also needs the utility service and meter to match.
What you get
Panel sizing. Each tile explains one result.
Calculated.
Size.
kVA.
Load.
Capacity.
A load management device can sometimes add an EV charger without a panel upgrade.
Frequently Asked Questions
No question matches that search.
What size electrical panel do I need?
Add up the loads using the demand method, divide by two hundred and forty volts and pick the next panel size.
Is a one hundred amp panel enough?
For a smaller home with gas appliances, often yes.
Do I need a two hundred amp panel for an EV charger?
Often, if the home already has electric heating, cooking and drying.
How is household load calculated?
General load per square foot plus appliances, with most counted at a reduced rate.
What voltage is a US home panel?
Two hundred and forty volts, split into two halves.
Can I upgrade my panel myself?
No. A licensed electrician and the utility must do it.
What is a load management device?
A unit that pauses some loads so a panel is not overloaded.
Power for today and tomorrow
Size the panel for the loads you have and the ones you plan, and future upgrades stay simple.
More size calculators
Each one has its own calculator, worked examples and answers to common questions.