How to calculate the IBU's of 2008 hops?

[aaron4osu]

I just bought an all grain setup from someone getting out of the hobby. He gave me all of his grain and hops as well. the hops were purchases in balk, repackaged in 3.5 oz. vacu-sealed bags, and frozen until now. I put them back in the freezer right after I got them. Anyway, is there calculator software available that takes into account say 2 year old cascade hops.

 

[wildwest450]

Yup, beersmith has a calculator for hops age.

 

[aaron4osu]

anything for mac? Beer alchemy doesn't, and i don't think homebrew formulator has it either. Anyone know what the time factor would be to multiply to the normal IBU equation?