Panel to house rating

How exactly do I know if let’s say 100 Amps is enough for a residence. I have a rough / general idea but would like to get better and more knowledgeable. Thanks.

!00 amps is the minimum for new construction and determining the adequacy of the electric for the house is not part of our SOP, Josh.

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To accurately determine the minimum service size you would need to perform a load calculation. As Larry stated the minimum for a dwelling is 100 amps. If you want to play around with how the calculation is performed Mike Holt has a free residential load calculator here:

Not required to do that. As Larry stated. 100 is a referred minimum ampacity.
Note SUSPECT if you think SEC, panel board or main disconnect are under rated, and think well.

Note equipment and main disconnect ampacity.
You can go further by inspecting and reporting SE/SEC AWG and reflected ampacity noted on cables or using a feeler gauge set.

Label on the panel board will list required equipment and any MAX ratings.

Thanks everyone. I did know about the 100 amps but sometimes I get people that may ask if they add a central air unit if they need to upgrade, or some other type of unit. Would just be nice to be able to be more knowledgeable to at least let them know when they should do a panel upgrade, or if they would be sufficient adding other items to the panel.