Compression Readings, which one ?

[C J R]

Hi Guys,
Sorry if this question has been asked before, but I tried a search and it did not provide the answer, so here goes.
 
I am trying to learn as much as possible about these cars, before purchasing one.
After researching other threads on this site, I realise one of the key questions before buying a car, is to verify the engine history, moreover one with a rebuild from a reputable builder is the best option.
 
I am interested in a car, twin turbo, looks to have had some work done on the engine, owner states 276 bhp with 221 lbs torque with a compression reading of 125 psi for each rotor.
From the other threads I have gleened an engine with readings of 7.0 or 8.0 are excellent, but can someone advise the formula for converting from psi to X.X, or is 125psi good ?
 
Many thanks
Chris :3Confused

[Timmy]

If they\'ve give you compression in psi it hasn\'t been done with a rotary tester, therefore is of little relevance to you. You will need the 6 individual results from a rotary compression test to have a real idea of the engines condition and that will be in bar instead of psi.
125psi is about 8.5bar which is very high so unless its a fresh rebuild i would be warey.