There are 1.65 trillion barrels of proven oil reserves in the world as of 2016.
The world has proven reserves equivalent to 46.6 times its annual consumption levels. This means it has about 47 years of oil left (at current consumption levels and excluding unproven reserves).
This means that the oil is going to run out in our lifetime
Source/more reading: https://www.worldometers.info/oil/
Update: It is infact not true (or just partially true), because it only considers already known oil reserves that can be pumped out with current technology.
There is more oil that can potentially be used as technology and infrastructure advances, so the estimate of 50 years is wrong.
For the correction thanks to Cephalotrocity@biglemmowski.win (their original comment)
I was curious how best to cut down on our usage, if we’d be aggressive, how long we could make our oil last.
From the EPA, seems the like roughly 40% of an oil barrel ends up being used to create gasoline source. The transportation sector accounts to 2/3 of our total oil consumption. In the transportation sector, roughly 54% of energy is used just for passenger cars. source
If everyone in the world stopped driving gasoline cars and switched to a 100% renewable option, we would only cut our oil production by about 36%. That changes the timeline from 50 years to 78 years.
Pretty saddening to think about. Hopefully some technology improvements for oil recycling come around quickly