If its fully synthetic oil, change every 10,000 kms or once a year (if you don't reach 10,000 kms).
For mineral, change every 5,000 kms or twice a year (if you don't reach 5,000 kms before a change interval).
If you don't rack up mileage like a taxi, the above guideline is not that expensive to follow. Its maintenance. Depending on how you see it, its a cost penalty in order for the vehicle to be able to serve you reliably in the years to come.