If you are serving a number of different sentences that ‘cumulatively’ add up to more than 2 years, then this will be treated as one long-term sentence (called a notional single sentence) for the purposes of figuring out your sentence length.
For example:
If you are sentenced to 1 year imprisonment, with another cumulative sentence of 1 year and another cumulative sentence of 2 years.
1 year + 1 year + 2 years = 4 years
4 years = 1460 days (365 x 4)
One third of 1460 = 486.6 (rounded up to 487)
Your sentence is for 1460 days, but you will be eligible for parole after 487 days.
Note: Sentence calculations are different if you were sentenced before June 2002.