I checked mine - I get 12-7/8 when I measure from the full line to where the dipstick cap seats on the tube when you thread it in.
That's also somewhat flattening out the dipstick - so if you were to use a longer dipstick, you'd want 12-7/8 from the end of the tube to just touch the top of the oil.
That's also somewhat flattening out the dipstick - so if you were to use a longer dipstick, you'd want 12-7/8 from the end of the tube to just touch the top of the oil.