1/4 size - It measures 37.4 inches and is the smallest of the double bass. This is the size that's recommended for children.
1/2 size - It measures 40.2 inches and will be suitable for older children to adults who are around five feet four inches in height.
3/4 size - It measures 43.7 inches and is the size most commonly used by musicians.
4/4 size - It measures 45.7 inches and is the largest size of the double bass. Few players are capable of playing this size but some claim that it sounds better than the smaller double bass.