I had a 40 gallon or so of soil batched up but it is frozen. So I put up a couple of new batches. I do not measure but here's some idea of wtf I use.

40# bag of plain (any good local brand) potting soil, no nutes like Hyponex (MG without the time released nutes)
1 foot³ peat moss
40# bag composted and dried cow manure (or 20# worm castings)
4 gallons perlite
2 gallon vermiculite
three 'fist-fulls' dolomite lime

mix, 1/2 gallon water (maybe add half can of flat beer), mix

best if it can sit for a week or two before transplanting. Not used for seed starting.

Shov