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Generator Sizing Calculator

Running load plus the largest motor start, a growth margin, and the duty rating you actually need, expressed in kW and kVA.

Inputs

Inputs and assumptions

Standby and prime ratings allow a short 10% overload; continuous does not.

Result

Design load with growth margin
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Peak load with motor starting
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Alternator rating to specify
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Nameplate rating to specify
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Normal loading at nameplate
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What to check

  • Nameplate running and starting watts for every load
  • Manufacturer load-acceptance data for the largest motor

Related calculators

Screening-grade sizing. Manufacturer load-acceptance curves, ISO 8528-5 transient limits, and the adopted electrical code edition govern the final selection; an engineer signs off before hardware is ordered.

Saved calculations

Keep the assumptions with the result.

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