According to the app on my phone, the current rate is $1.21 for one pound.
I really don't know if that's too low or not. But I do know that when I was stationed in England in the 1970s for three years the rate was about $2.65 per pound and that was way, way, way too high. Probably about $1.80-2.00 would've been a fair rate.
In recent years, a measure known as purchasing power parity (PPP) has been developed that assesses currency values through a "basket of goods" approach that compares the cost of living between countries. Intuitively, that is also how consumers compare currency values, while financial analysts look at economic data like interest rates.
The pound-dollar has oscillated more or less around that rate for a few years now.