How to Calculate Electrical Load
What is Electrical Load?
Electrical Load Calculator helps contractors and tradespeople accurately size, spec, and estimate materials and systems.
Formula
Total Load = Σ (Wattage × Usage Hours) per circuit
Step-by-Step Guide
- 1List all devices on circuit, sum wattages
- 2Apply the formula using your project measurements
- 3Add required safety factors or waste allowances per code
Worked Examples
Input
Lights 300W + outlets 1200W + appliance 1500W
Result
Total Load = 3000W on 20A circuit = 25A → overloaded
Common Mistakes to Avoid
- ✕Not applying code-required safety factors or derating
- ✕Forgetting to account for waste and cut losses in material estimates
Ready to calculate? Try the free Electrical Load Calculator
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