200 amps is usually enough for a Level 2 charger and a heat pump in a typical house, which is why people are told it is the standard service size. It is not a guarantee once you stack a 48-amp charger, electric backup strips, a range and a dryer. The 200-amp combination walk-through on this site (a labeled example, not your house) landed around 131.4 A with 10 kVA of heating value, and around 152.2 A with 15 kVA — under 200 A, but not empty.
Older consumer articles that say “200 amps is enough for an average house of a certain size” predate this electrification stack. Use measured demand plus the new nameplates, or a proper calculated method, in the calculator, and have the HVAC and EV quotes share one sheet. If you are also planning an ADU or a second charger, say so now rather than after the heavy-up is finished.
This is not a permit calculation, a utility approval, or a substitute for a licensed electrician, HVAC contractor, or the authority having jurisdiction. Panel Headroom is an independent educational site. It is not a utility, a certification body, or a contractor. Electrical and generator work that is done incorrectly can cause fire, shock, or carbon monoxide poisoning. Use the adopted electrical code and manufacturer instructions; pull permits where required.