Mortgage Rate Estimation

[Mac Boeve]

Is there a good method to accurately determine what my mortgage rate would be without using a lender? 

The wife and I both have good credit, 10+ years of credit history, and work at W-2 jobs. We're looking at purchasing a multi-family property as either our main residents or an investment property. I'd like the ability to calculate what mortgage rate I can expect to get on different properties without having to use a lender each time.