Generator Sizing Calculator
ISO 8528 & NFPA 110 generator sizing with motor-start checks.
Get the right kW and kVA on the first try. EngineSuite handles steady-state load, motor starting, step-load classification, and harmonic considerations — and explains every assumption per ISO 8528 and NFPA 110.
What you get
Steady-state + motor starting
Compute connected load and largest motor inrush. Pick the right alternator class (G1–G4) for your transient performance need.
Step-load checks
Validate step-load acceptance per ISO 8528-5 so the genset doesn't stall on the largest start.
Emergency power compliance
Reports include NFPA 110 Class / Type / Level tags for healthcare and life-safety projects.
Unlimited calculators and AI. Pay only when you need a stamped PDF.
Every result tells you the exact clause behind the number.
Your firm's logo, project info, and citations — one click.
Frequently asked questions
Does it handle paralleled gensets?
Single-unit sizing is first-class. Paralleling and N+1 redundancy guidance is in the AI assistant.
Will it size for VFD and harmonic loads?
Yes. Add a harmonic distortion factor and the calculator de-rates the alternator accordingly.
Is EngineSuite free for students?
Yes. Students and EITs with a valid academic or professional email get free access to every calculator and the AI assistant. You only pay if you need a stamped PDF report.
Can I export branded PDF reports?
Yes. Every calculation can be exported as a one-click branded PDF with your company logo, name, and project metadata. Pro plans include unlimited exports.
Try it on your next project
Sign up free, run a calculation, and see the code citations for yourself.