Charges are listed at http://www.jetstar.com/au/en/plannin...hecked-baggage

If you have purchased luggage then, the excess fees are SGD20 per Kg, so 40 Kg would be $800


If you think you may be going high on luggage, then I suggest pre-purchasing what you can ( 40Kg )

When making the booking 40Kg of checked baggage can be selected per person for a cost of SGD65 per person on the cheapest booking type ( no need to purchase a max bundle ). Purchasing a max bundle is likely to be a v poor value way to get 20Kg baggage allowance ( just doing a dummy booking base fare $128 with plus bundle being an extra $176 - much cheaper just to purchase 40Kg luggage at $65 )