These do fit small and are a slim fit pant. They do have some stretch. Be sure to size up 1-2 sizes  

Please refer to size chart below. 

functioning pockets, zipper, and button  

Approximate measurements:

length measurements are waist to floor

0/3 month:  length: 13.5, waist: fits 13 inches to 15 inches 

3/6 months:

6/12 months length: 16.5, inches waist: fits 13.5 inches-15.5 inches 

12/18 months length: 17 inches, waist fits 14 inches- 16 inches 

18/24 months length: 18 inches, waist: fits 15 inches-17 inches 

2T length: 19 inches long, waist fits 15.5 inches-17.5 inches 

3T length: 22 inches long, waist: fits 16.5-18.5 inches

4T length: 24 inches long, waist: fits 18-21 inches 

5/6 length: 26 inches long, waist: fits 19-22 inches

6/7 length: 

7/8 length:

8/9 length: 31 inches long, waist: fits 22-25 inches 

10/12 length: 33 inches long, waist fits 22.5-25.5 inches 

14/16 length: 34.5 inches long, waist fits 24-28 inches