To calculate your equity, you divide the amount to call by the sum of the amount already in the pot and the amount to call. In this case, 95/(235+95) or 95/330 comes out to 28.79%. The worst possible cards he can have still have you winning 36% of the time, so like I said before even if he flips his hand face up your 36% equity is still better than the pot equity (you only need to win 29% to break even). When you take into account his range of possible holdings, you probably are closer to 45% or 50% equity against all hands he can hold, so it becomes an even easier call to make.