Electrical Load Balance Calculator

Summary

Add loads, assign each to a phase, and instantly see per-phase wattage and the imbalance percentage for single-phase 2-leg or 3-phase systems.

How it works

1. Select system type: 3-phase (A/B/C) or single-phase 2-wire (L1/L2).
2. Click "Add Load" to add a row for each circuit or appliance.
3. Enter the load name and wattage for each row.
4. Assign each load to a phase using the dropdown.
5. Read the per-phase totals and imbalance percentage in the results panel.
6. Aim for imbalance below 5% for residential and below 2% for commercial systems.

Use cases

• Balance branch circuits across a 3-phase commercial or industrial panel.
• Check phase imbalance before commissioning a new electrical installation.
• Plan load distribution when adding new equipment to an existing panel.
• Verify that a single-phase 2-wire service has roughly equal legs.
• Document load balance for permit or inspection requirements.
• Identify which phase is overloaded so circuits can be moved.
• Optimize generator load distribution to reduce fuel consumption.
• Teach electrician apprentices about phase balancing principles.

Frequently Asked Questions