What Size Is a Baseball Card? Standard Dimensions Explained

[Brock Purdy]

I appreciate recent the shift towards interest in card collecting as there appears to be gaps in knowledge that exist in the field. Would you be able to elucidate What Size Is a Baseball Card? of these cards as of today?

I understand that modern cards of any type tend to be made in standard sizes so these dimensions are of burning interest to me.

What are the dimensions of standard baseball cards in inches and millimeters?

Have the dimensions of the cards changes to any cards in the vintage or early sets?

Does any of the brands like Topps, Upper Deck, Panini, etc. keep uniform standards in dimension or is there certain disparity?

What are the most effective ways to protect and store baseball cards given these standard dimensions like sleeves, toploaders, or even binders?

I admit that I wish to attain the proper protective equipment so that I can organize my storage in the best possible fashion. I am certain I am not the only one so I appreciate any knowledge you are able to share concerning intriguing and unarguable standardizations along with the exceptions that might come with these cards.