The National Treasury Management Agency (NTMA) sets the variable percentage rate used to calculate the prize fund. Effective from August 2017 this variable percentage rate is set at 0.50% of the total value of Prize Bonds outstanding.
At the end of December 2017, the value of Prize Bonds fund was €3.1 billion. The value of the prize fund is recalculated at the end of every month, in line with the monthly net sales of Prize Bonds.
See the current Prize Structure here.