How to Calculate Panel Load
What is Panel Load?
Panel Load Calculator helps contractors and tradespeople accurately size, spec, and estimate materials and systems.
Formula
Panel Load % = Total Connected Load / Panel Capacity × 100
Step-by-Step Guide
- 1Sum all breaker amperages × voltage, divide by panel rating
- 2Apply the formula using your project measurements
- 3Add required safety factors or waste allowances per code
Worked Examples
Input
150A panel, 120A total load
Result
Load = 120/150 × 100 = 80% (aim below 80%)
Common Mistakes to Avoid
- ✕Not applying code-required safety factors or derating
- ✕Forgetting to account for waste and cut losses in material estimates
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