So how do you determine what size diamond to buy? Do you want a diamond carat of 1, or 2, or do you want a ring with multiple, smaller stones? The answer to this will depend greatly on your budget, as well as the person who will be wearing the ring.
A diamond will look larger on a slender finger, so keep that in mind if the recipient of the ring has thin hands. The actual diamond carat measurement is probably not as much of a concern as the appearance, shape, and setting of the ring. Particularly because a 1 carat diamond ring will not look half the size of a 2 diamond carat ring, it's far more important to select a ring that is pleasing to look at than it is to buy one with the most carats you can afford.