I have a very skinny 19 month old son and these were great! In the product description it says it has an elastic waist in the 18m size but to our surprise it also has an adjustable waistband  (at least ours did) The 18mo fit him great once we tightened the waistband. The length and adjustable waistband will allow room for growth and that's always a plus.

They say skinny jeans but thankfully they're not painted on, they look like the relax straight fit for adult men...my little guy loves them and they go great with anything. Will definitely recommend them and purchasing them again a few sizes up. Love it!