Generator Sizing Tool
Calculate the right standby generator size for your facility based on critical loads, motor starting surges, and future growth requirements.
Calculate
What Size Generator Do You Need?
Add your critical loads and we'll calculate the recommended generator capacity, transfer switch size, and fuel consumption.
Critical Loads
Set the quantity for each load your generator must power.
Server Rack (per rack)
3.0 kW running
UPS System
5.0 kW running
HVAC Unit (5-ton)
6.0 kW running · 3× starting surge
Lighting (per floor)
2.0 kW running
Elevator Motor
7.5 kW running · 4× starting surge
Air Compressor
3.0 kW running · 3× starting surge
Water/Fire Pump
5.0 kW running · 5× starting surge
Workstation Cluster (10)
3.0 kW running
Growth Margin: 20%
Additional capacity for future load growth beyond current requirements.
Fuel Type
Why This Matters
Get Generator Sizing Right the First Time
An undersized generator fails under load. An oversized one wastes fuel and capital. Get the numbers right before you buy.
Prevent Undersizing
Motor starting surges can be 2-6× running watts. Our calculator accounts for worst-case surge to prevent generator overload.
Budget for Growth
Adjustable growth margin ensures your generator investment handles future load additions without costly upsizing.
Complete Specifications
Get generator kW rating, transfer switch sizing, and fuel consumption estimates — everything your electrician needs.
Related Services
Need a complete backup power solution designed and installed? Our team handles generator installations, UPS integration, and automatic transfer switches.
Need a Professional Power Assessment?
Our licensed electricians and engineers will assess your facility's power needs and design a complete backup power solution — generator, UPS, and automatic transfer switch.