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
Estimate the minimum service amperage your home's electrical panel needs based on lighting, kitchen appliances, and HVAC loads. Use this before upgrading a panel or planning a new home build.
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 | 3 |
| Result | Maximum Wire Connections (wires) | Panel Capacity Needed (amps) |
| 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. | Estimate the minimum service amperage your home's electrical panel needs based on lighting, kitchen appliances, and HVAC loads. Use this before upgrading a panel or planning a new home build. |