For every actual flown mile, you earn points based as follows:
First Class: 1.50
Business Class: 1.25
Full-Fare Coach (Y Class): 1.00
Discount Coach (all other coach fares): .50

Say you are flying a route which is 1,000 actual flight miles. If you are in discount economy, you get 500 Q-Points. Full-fare coach gets 1,000 Q-Points. Business Class gets 1,250 points. Finally, First Class gets 1,500 points.

Hope this helps.