The basic Prayer Shawl should measure about 20 inches wide and 60 inches long.  However, variations are fine, because of various sizes of needles used and weights of yarn. 

Knitted Basketweave Shawl

Yarn	3 skeins of worsted weight
Needles	size 11
Guage	11 1/4 stitches = 4 inches of basketweave
Cast on	56 stitches

Basketweave pattern: (multiple of 12 + 8)

Row 1 (Wrong Side): P
Row 2: P8, K4, P8
Row 3: K8, P4, K8
Row 4: rep row 2
Row 5: P
Row 6: P2*, K4, P8, K4, repeat from*, ending P 2
Row 7: K2*, P4, K8, P4, repeat from*, ending K 2
Row 8: rep row 6