Premiums Earned, also reported as Revenue from Premiums measures the total amount of premiums that the insurance company considers to be "earned" because the insured has not claimed losses within a specified time.
This metric is calculated by multiplying the original premium value by the percentage of time that the policy has been in effect without having a claim filed. For example, if a $1,000 policy (premium) has a 2 year life span and no claim has been filed 1 year into the policy, the premium earned equals $500 ($1,000 x (1/2)).
This metric is distinct from Premiums Written in that when an insurance policy is written (IE a customer signs up) the premiums may be used to pay losses incurred.