Compare calculators
Both calculators run independently — change the inputs on either side to compare results.
Electrical Home
Electrical Box Fill Calculator
Calculate how many additional wires fit in an electrical junction box after accounting for installed devices. Critical for NEC compliance when adding wires or devices to an existing box.
Fill in the required fields to see your result.
Electrical Home
Electrical Panel Load Calculator
Calculate your home's total electrical panel load and remaining capacity in volt-amperes, so you know whether your panel can support new appliances, an EV charger, or a home addition. Use it before calling an electrician for a panel upgrade assessment.
Fill in the required fields to see your result.
Key differences
| Electrical Box Fill Calculator | Electrical Panel Load Calculator | |
|---|---|---|
| Category | Electrical Home | Electrical Home |
| Inputs required | 3 | 5 |
| Result | Maximum Wire Connections (wires) | Available Panel Capacity (VA) |
| What it does | Calculate how many additional wires fit in an electrical junction box after accounting for installed devices. Critical for NEC compliance when adding wires or devices to an existing box. | Calculate your home's total electrical panel load and remaining capacity in volt-amperes, so you know whether your panel can support new appliances, an EV charger, or a home addition. Use it before calling an electrician for a panel upgrade assessment. |