The unwritten rule of thumb is that petite women should usually opt for slim, narrow belts while tall women can indulge in wide ones. Of course, any belt can make your waist appear wider than it is based upon where on your body you wear it. (on your hips vs. the middle of your waist). Depending on your size, belts worn up high on your waist can make you look wider. So, if this is your concern, wear your belt low on your hips. However, your dimensions sound pretty small so I wouldn't ever worry about looking wide!