The yorkie breed standard size for the show ring is 8 - 9 inches tall at the shoulders, but can be shorter or taller. Weight is approximately 4 - 7 lbs but can be smaller are larger, depending on bone structure etc. This doesn't mean they are not pure bred just simply means they are pet quality and not show quality! A pure bred yorkie puppy will be born black and gold, some stay black & gold when they are grown. However most turn blonde/tan and silver or steel blue and blonde/tan. They have human like silky hair that can grow floor length. This makes grooming high maintenance. If not kept short they require daily brushing, or they can become severely matted. They are a non-shedding breed. Some yorkies ears natural stand erect, but most yorkies ears require taping to stand erect. If they are going to stand naturally, they should be erect by 12 - 14 wks of age. They have an average life span of 13 - 16 yrs, but some have lived to be in their 20's. Very independent little fun loving dogs!
I consider Teacup yorkie to be under 5 lbs grown. There is really no such thing as a full grown dog that will fit in a teacup. Teacup is just a word used for a tiny little dog!