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Generator Size Formula:
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Generator size calculation determines the appropriate generator capacity needed to power your home appliances and systems during a power outage, ensuring reliable backup power.
The calculator uses the formula:
Where:
Explanation: The formula converts total wattage to kilowatts and adds a 25% safety margin to account for startup surges and future expansion.
Details: Proper generator sizing ensures your backup power system can handle the electrical load without overloading, provides reliable operation, and extends the generator's lifespan.
Tips: Enter the total wattage of all appliances and systems you want to power. Make sure to include both running watts and startup surge watts for accurate calculation.
Q1: Why is a safety margin needed?
A: The 25% safety margin accounts for startup power surges that can be 2-3 times higher than running watts and allows for future electrical load additions.
Q2: How do I calculate total watts?
A: Add the wattage of all appliances you plan to run simultaneously. Check appliance labels or manuals for wattage information.
Q3: What's the difference between running and starting watts?
A: Running watts are the continuous power needed, while starting watts are the extra power needed for motor startup (typically 2-3x running watts).
Q4: Can I use this for whole house vs portable generators?
A: Yes, this calculation works for both whole-house standby generators and portable generators, though whole-house systems typically require professional installation.
Q5: What if I have high-demand appliances?
A: For appliances with high startup surges (AC units, refrigerators, pumps), make sure to include both running and starting watts in your total calculation.