Points and miles do not usually have real cash value, but a value between $0.01 and $0.02 per point/mile is common.
Most airline loyalty programs issue some form of points or miles. These are awarded for flights taken (and increasingly in other areas such as retail and credit card spending) and can be exchanged for free or reduced-price flights, upgrades, or in limited other areas. To determine value, we need to look at what they are typically used for.