How can I determine whether a call is a local or toll call?

You can dial the 10-digit number and if you get automated response..."you can't call the number as dialed"...it's probably long distance.

I should add.  I live in the 760 area code in California.  There are are a lot of 858 area code phone number that are not toll calls.   I just don't know which ones.

Does this help? Looks like a break down of the local calling area for San Diego, CA.