Generator Size Calculator Ireland
Choose a home or business profile to estimate likely running demand, allow for starting loads and compare SolarBoss generator capacity options. Refine the assumptions whenever you need to. Free to use, with no email required.
Profiles are illustrative managed-backup estimates, not measured household averages or a certified electrical design. Large heating loads, EV charging and specialist machinery need their own assessment.
Understanding your generator size estimate
Continuous power is the running output to compare with your estimated simultaneous demand. Starting power is a brief event for motors and is checked separately. The default planning allowance is 25% above the higher-use running estimate. Tank runtime depends on load and the exact generator version; it is not a promise of unrestricted continuous operation.
Generator sizing questions
Does everything in my home need to run at once?
No. The profiles allow background demand and occasional use. Refine lets you mark equipment as running together or one at a time.
Can this size whole-house backup?
It provides a planning estimate for selected loads. Electric showers, immersion heaters, EV chargers, heat pumps and large machinery are not included in the simple profiles.
What about three-phase power?
Total kW does not establish phase balance or per-phase and socket limits. A three-phase assessment is needed before matching a generator.
Can a generator work with my solar inverter?
Compatibility depends on the exact inverter and generator models, AC input limits, phase and controls. Automatic starting alone does not prove AC compatibility.
All premises connections need a Registered Electrical Contractor, suitable isolation and changeover equipment. Run combustion generators outdoors away from openings. Never backfeed through a socket.
Read the complete generator buying guide · Generator and Solis inverter compatibility · Shop generators · Diesel generators · Petrol generators