According to most websites I consulted when estimating my needs, a 3.8 cu ft bale will expand to 7.5 cu ft, so it roughly doubles. And when I actually opened the bags I found this estimate to generally hold.

thank you .
jim

another question , about how much lime per bale of peat to nuetralize it ?
jim

I never got 7 cu ft out of my peat bales. It was my understanding that it is 3.8 cu ft that has been compressed, so it will expand back to 3.8 cubic foot uncompressed. The bales that I got were definitely not 3ftx1ftx1ft compressed in size.

That's what I went by when I caclulated first filling my bed, and I still didn't have enough peat. Once you wet it down it compresses even further!

The 3.8 cuft compressed bales I've been getting are definitely 3.8 in size. I can't say for sure it expands to 7 cu ft, but as I broke it up and scooped it from the bag, it would just expand and fill the bag again. Seemed like it took forever to get the level in the bag to go down at all.

Here is a link that might be useful: Using Peat Moss