A transparent planning estimate, not a quote: list your home's loads the way an installer's survey will, apply the 80 percent rule, and get a recommended kVA bracket plus an indicative installed budget band (EUR). The methodology is explained in the generator sizing guide.
Water and pumps
Special loads
Coverage
Recommended standby size
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Indicative planning figure (ASSUMPTION) — confirm with a RECI-registered installer's site survey and your appliances' nameplates. Budget band: indicative 2026, installer quotes vary.
How this estimate works
The calculator follows the method in our sizing guide: it totals the running watts of the circuits you select, adds a motor start-up surge allowance for the largest pump or compressor, multiplies the continuous load by 1.25 (the 80 percent rule), and converts to kVA at a 0.8 power factor before rounding up to a standard rating bracket. See the installation guide for what happens next, and the cost guide for how quotes break down. There is no SEAI grant for generators — plan for the full installed cost.