Technically, pedometer readings can widely vary. For example, if you were to wear 2 pedometers, you may have 2 different readings (even off by 1,000 or more steps). Stride length also comes into consideration, too.
...but as a a guide, 10,000 can be in the neighborhood of 5 miles
A quick google search tells me that the average stride length for a female is 2.2 feet. Since there are 5280 feet in a mile (I had to look that up, too, lol.. I'm scientist, I think in metric!) each mile is about 2400 steps. So, 10,000 steps is 4.16 miles.
Since pedometers aren't perfect, I'd say 5 miles is a good estimate... even if you're really short or really tall, I'd guess it's somewhere between 3 and 6 miles.
That's the approximate measure I use, yes. As others have said, it obviously varies according to stride and the reliability of the pedometer but 2,000 steps = 1 mile is a good and easy to use measure to stick to as a general guide.
I trust myself. I have started so I will finish. I am succeeding.