These jeans run closely to true-to-size...though slightly smaller, because they are skinny jeans. So it depends on how "solid" and "thick" your build is. If you're thicker-I'm sure they will still fit, although very snug. I get the feeling if I were to go up a size (I'm an 18, thick), then it would be too big.
After further research, this item runs true-to-size, so buying the size you normally wear will be fine. Here is a general size chart for more information.
What are the waist measurements for size 14 as most buyer have said it runs small and I would like actual measurements of the waist and hips please in size 14.