What Size Generator Do I Need? Sizing for Homes, Worksites and Farms
Generator sizing is arithmetic, not guesswork — and undersizing is the most expensive mistake a buyer can make: an overloaded generator stunts motor-driven appliances, overheats and dies early. Three numbers decide everything.
1 · Running watts.
Add the continuous wattage of everything that will run together. Typical ranges: refrigerator 100-800 W, lights and fans 100-500 W, television 100-400 W, water pump 750-1,500 W, air conditioner 1,000-3,500 W.
2 · Starting surge.
Motors draw 2-3 times their running power at startup — compressors (fridge, AC) and pumps are the usual culprits. Your generator must cover the total running load plus the starting surge of the single largest motor, not all motors at once.
3 · Headroom.
Add roughly 20%. A generator run at 100% of rating ages fast; one run at 80% lasts. Worked example: a home with fridge (700 W) + lights (300 W) + TV (200 W) + a 1,500 W well pump with 3× surge needs about 1,200 W running + 3,000 W surge → a 4-5 kW unit is the right neighbourhood. For construction sites and farms running pumps, welders or grain mills, open-frame industrial sets from 25 kVA down are the proven choice.
Two more checks before ordering.
Frequency: buy the variant engineered for your grid — 50 Hz or 60 Hz — and confirm it before shipment. Fuel: dual-fuel (petrol/LNG) sets hedge against fuel price swings and supply interruptions.
Our generator line spans 1.2 kW digital inverters (retail, quiet) to 25 kVA industrial open-type sets, every model engineered in 50 Hz and 60 Hz variants, with LNG dual-fuel options across the range. Send your appliance list or pump/welder ratings through the RFQ desk and we will size the set and quote with the factory specification sheet within 24 hours.