Here’s my own cheat sheet (for the tool method aka hair folded in half and for saran, though I use the same amount of nylon as it tends to be lossy during prep/work).
To calculate the size and number of hanks / skeins to buy :
It takes 3 + 1 half (about 40g) , cut in half , to cover a 5/6″ head with very long hair.
1 “hank” of Retrodolls saran is about 90cm and 12g therefore:
A hank can be cut in 3 = length on the doll 14cm max from roots to ends. 2 hanks per reroot.
A hank can be cut in 2 = length on the doll 20 – 22cm. 4 hanks per reroot.
1 “Skein” of Mylittlecustoms/Restoredoll saran is 46cm and 12g, it contains as much hair as a hank but it is shorter.
4 skeins for a reroot = length on the doll 23 cm.
1 “XL Skein” of Mylittlecustoms/Restoredoll saran is 76cm and 40g, it contains approx. 3 and 1/3 hanks/skeins of fiber.
1 whole reroot (Cut in 2) = length on the doll 19cm.
1 “Large Hank” of Retrodolls saran is 90cm and 50g (contains just over 4 hanks)
1 “XL Hank” of Retrodolls saran is 90cm and 100g (contains 8 hanks)
Not using dollyhair hanks any more as they were averaging 8-9g.
See https://docs.google.com/spreadsheet/ccc?key=0As0WIngBCIdZdFIzRUdFZmZONktVNzM2eUd5STczVWc#gid=2 for the colour matches between sellers.
If you’re looking to measure your doll’s hair in inches, please see NoNapTime’s awesome tutorial: http://www.nonaptime.com/2015/02/calculating-the-amount-of-hair-needed-for-a-reroot