How long does it take to get from Dallas/San Francisco to London?

Question

Hey everyone. I'm currently working on a story where my character and her friend go to London. I need to know aproximately how long it would take to get from San francisco to London, and then Dallas, Texas to London. I would really apreciate some help. Thanks!

Answer 1

Call the airline thats going that direction.

Answer 2

I' d say approx 12 -15 hours for both destinations .