How quickly does one get tolerance to opiates? I'm on oxcycontin 20mg and just wondering what I should expect for increases in dosage

See Answer below. Opiates are complicated. A physician needs to make sure that you need to be on this specific class of medication and prescribe the smallest effective dose for the shortest time period needed. People will almost always need increasing dosages with long term use. With increasing dosages come increasing adverse events such as constipation and dependence.
Variable. Everyone is different. It is not something that occurs in a matter of days but rather something to look at over a period of many weeks to months. The same dose of medication does not yield the same analgesic effect.