Crowns For Gap in Front Teeth. Will Crowns Be Big?

It all depends on how large the gap between the teeth are.  If small, generally composite bonding or two porcelain veneers or two porcelain crowns will do the trick.  If large, than oftentimes better to treat the four front teeth, this enables the dentist to distribute the space among four teeth, getting much more natural proportions without the two front teeth appearing over large compared to the others.  And in some cases, six or eight porcelain veneers may be the best way to go.  Suggest discussing the results with your dentist before treatment begins. He can have a "diagnostic waxup" made in advance for you to see how two crowns or veneers would look.  Better to know what you're getting before hand than to be disappointed later on.

Sometimes if the gap is large, placing 2 crowns is not enough. The crowns may appear too large, placing 4 crowns can balance out the gap and look more asthetically pleasing.

It is very difficult to determine this without a image but what you need is to have a esthetic analysis where the dentist will determine if the tooth proportion obtained by the crowns would be the correct one in order to have a esthetic outcome, this is done by doing some casts and a esthetic wax up and then a mockup in your mouth in order for you to see the end result before even touching your teeth.