Central electric heat is the whole-house version of a space heater: large elements or an electric furnace / heat pump backup, shared through ducts. Watts are much higher than a plug-in tower. Runtime follows outdoor temperature and the thermostat, not how “on” the house feels.
A heat pump in mild weather can be far cheaper than straight electric resistance. The same system on a very cold day may switch to strip heat — and that is when the bill jumps. Whatt cannot see your outdoor reset curve. You set the kind of system and the hours it actually ran.
Closing vents in unused rooms is not a reliable savings trick on many ducted systems; it can raise static pressure and not cut compressor or strip time the way people hope. Setpoint and hours are the honest levers.
Pick the closest system size and the hours of heat. Climate on the results screen (when it applies) is about outdoor temperature, not a weather forecast bill.
If strip heat is about 10,000 watts for 4 hours, that is 40 kWh. At 18.8¢ that usage line is about 7.52 that day. A heat-pump-only day at a lower average wattage is a different card setting.
Gas furnace
On the central heat card, pick gas furnace · blower only if the heat is gas. Fuel then sits in the total. Blower-only without that setting undercounts a gas house.
Related
Usage estimate only — not a utility bill, load calc, or advice.